All questions of Geometry for CTET & State TET Exam

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The angles of a quadrilateral are in the ratio 4: 5: 10: 11. The angles are
  • a)
    36°, 60°, 108°, 156°
  • b)
    52°, 60°, 122°, 126°
  • c)
    48°, 60°, 120°, 132°
  • d)
    60°, 60°, 120°, 120°
Correct answer is option 'C'. Can you explain this answer?

Raghav Bansal answered
 Let x be the common angle among all the four angles of a quadrilateral.
As per angle sum property, we know:
4x+5x+10x+11x = 360°
30x = 360°
x = 12°
Hence, angles are
4x = 4 (12) = 48°
5x = 5 (12) = 60°
10x = 10 (12) = 120°
11x = 11 (12) = 132°

If PQR is an isosceles triangle and M is a point on QR such that PM⊥QR,then
  • a)
    PQ2−PM2 = QM2−MR2.
  • b)
    PQ2+PM2 = QM.MR.
  • c)
    PQ2−PR2 = QM2 − MR2
  • d)
    PQ2−PM2 = QM.MR.
Correct answer is option 'C'. Can you explain this answer?

Krishna Iyer answered
 
Since, in a triangle the sum of squares of any wo sides is equal to twice the square of half of the third side together with twice the square of the median bisecting it.
In ΔPQM,

In the adjoining figure D, E and F are the mid-points of the sides BC, AC and AB respectively. ΔDEF is congruent to triangle :
  • a)
    ABC
  • b)
    AEF
  • c)
    AFE, BFD and CDE
  • d)
    CDE , BFD
Correct answer is option 'C'. Can you explain this answer?

Raghav Bansal answered
Given :△ABC, F, D and E are mid points of AB, BC, CA respectively.
Using mid point theorem we prove that □AEFD, □DBFF and □DCEF are parallelograms. The diagonal of a parallelogram divides the parallelogram into two congruent triangles. So all triangles are congruent to each other. So ΔDEF is congruent to 
△AFE, △BFD and △CDE

  • a)
    ∠B=∠D.
  • b)
    ∠B=∠E.
  • c)
    ∠A=∠D.
  • d)
    ∠A=∠F.
Correct answer is option 'A'. Can you explain this answer?

Manisha reddy answered
Given information:
- QR < 2pq="" -="" />
- PR = PQ + 10
- Perimeter = 40

To find:
- Smallest side of the triangle PQR

Solution:
Let's assume that PQ = x, QR = y, and PR = z.

Using the given information, we can write two equations based on the lengths of the sides:

1. y = 2x - 2 (QR is less than twice the length of PQ by 2 cm)
2. z = x + 10 (PR exceeds the length of PQ by 10 cm)

We also know that the perimeter of the triangle is 40 cm:

x + y + z = 40

Substituting the values of y and z from equations (1) and (2) into equation (3), we get:

x + (2x - 2) + (x + 10) = 40

Simplifying the equation, we get:

4x + 8 = 40

4x = 32

x = 8

Therefore, the length of the smallest side of the triangle PQR is PQ = x = 8 cm.

Answer: Option (B) 8 cm.

If bisectors of ∠A and ∠B of a quadrilateral ABCD intersect each other at P, of ∠B and ∠C at Q, of ∠C and ∠D at R and of ∠D and ∠A at S, then PQRS is a
  • a)
    Rectangle
  • b)
    Quadrilateral whose opposite angles are supplementary
  • c)
    Parallelogram
  • d)
    Rhombus
Correct answer is option 'B'. Can you explain this answer?

Ananya Das answered
To show: ∠PSR + ∠PQR = 180°
∠SPQ + ∠SRQ = 180°
In △DSA,
∠DAS + ∠ADS + ∠DSA = 180° (angle sum property)
+ ∠ SA = 180° (since RD and AP are bisectors of ∠D and ∠A)
∠DSA = 180°
∠PSR = 180°−
(∵ ∠DSA = ∠PSR are vertically opposite angles)
Similarly,
∠PQR = 180°− 

Adding (i) and (ii), we get, ∠PSR + ∠PQR = 180°
=360° − 1/2 ​× (∠A + ∠B + ∠C + ∠D)
 
=360°− 1/2​ × 360° = 180° ∴ ∠PSR + ∠PQR = 180°
In quadrilateral PQRS,
∠SPQ + ∠SRQ + ∠PSR + ∠PQR = 360°
=> ∠SPQ + ∠SRQ + 180° = 360°
=> ∠SPQ + ∠SRQ = 180°
Hence, showed that opposite angles of PQRS are supplementary.

The areas of two similar triangles are 100cmand 49 cm2. If the altitude of the larger triangle is 5 cm, then the corresponding altitude of the other triangle is equal to
  • a)
    3.5 cm.
  • b)
    3.9 cm.
  • c)
    5.4 cm.
  • d)
    4.5 cm.
Correct answer is option 'A'. Can you explain this answer?

Krishna Iyer answered
Let the two similar triangles be ΔABC and ΔDEF such that ar(ΔABC) = 100 cm2 and ar(ΔDEF) = 49 cm2.
Let AM and DN be the respective altitudes of ΔABC and ΔDEF.
Since the ratio of the areas of two similar triangles is equal to the ratio of the squares of their corresponding altitudes

The line segments joining the mid points of the sides of a triangle form four triangles each of which is :
  • a)
    Similar to the original triangle
  • b)
    Congruent to the original triangle
  • c)
    An equilateral triangle
  • d)
    An isosceles triangle
Correct answer is option 'A'. Can you explain this answer?

Krishna Iyer answered
Given :△ABC, D, E and F are mid points of AB, BC, CA respectively.
Using mid point theorem we prove that □ADEF, □DBEF and □DECF are parallelograms. The diagonal of a parallelogram divides the parallelogram into two congruent triangles. So all triangles are congruent to each other. And each small triangle is similar to the original triangle.

In ΔABC, AB = 3 cm, AC = 4 cm and AD is the bisector of ∠A. Then, BD : DC is :
  • a)
    9 : 16
  • b)
    16 : 9
  • c)
    3 : 4
  • d)
    4 : 3
Correct answer is option 'C'. Can you explain this answer?

Recent years, there has been an increasing focus on mental health and the importance of taking care of it. This is due to a growing recognition of the impact mental health has on overall well-being and the understanding that mental health issues are common and can affect anyone.

One reason for the increased focus on mental health is the rising prevalence of mental health disorders. According to the World Health Organization, one in four people in the world will be affected by mental or neurological disorders at some point in their lives. This means that mental health issues are widespread and can have a significant impact on individuals, families, and communities.

Another reason for the increased focus on mental health is the growing understanding of the link between mental health and physical health. Research has shown that mental health issues can lead to a range of physical health problems, including heart disease, diabetes, and obesity. Conversely, taking care of mental health can improve physical health outcomes and overall well-being.

Additionally, there has been a greater recognition of the stigma surrounding mental health and a push for more open discussions and conversations. People are becoming more willing to share their experiences with mental health and seek help when needed. This increased openness has contributed to a greater understanding and acceptance of mental health issues, leading to more resources and support being available.

In recent years, there has also been a growing emphasis on mental health in the workplace. Employers are recognizing the importance of supporting their employees' mental well-being and implementing measures to promote mental health in the workplace. This includes initiatives such as employee assistance programs, mental health training for managers, and creating a supportive work environment.

Overall, the increased focus on mental health in recent years is a positive development. It has led to greater awareness, understanding, and support for mental health issues. However, there is still work to be done to ensure that everyone has access to the resources and support they need for their mental well-being.

ABCD is a Rectangle. Find the values of x and y?
AB =30 DA= 14 DC= x+y CB=x-y
  • a)
    20 and 10
  • b)
    25 and 5
  • c)
    24 and 6
  • d)
    22 and 8
Correct answer is option 'D'. Can you explain this answer?

Om Chawla answered
ABCD is a rectangle.
∴ AB = CD
⇒ 30 = x + y
or x + y = 30 ..... (i)
Similarly, AD = BC
⇒ 14 = x - y
or x - y = 14 .......(ii)
On adding eq. (i) and (ii), we get
2x = 44
⇒ x = 22
Putting the value of x in eq. (i), we get
22 + y = 30
⇒ y = 30 -22
⇒ y = 8
So, x = 22, y = 8.

ABCD is a Rhombus. Then, find the value of x and y?
  • a)
    40 and 40
  • b)
    35 and 35
  • c)
    37 and 37
  • d)
    45 and 45
Correct answer is option 'B'. Can you explain this answer?

Parina Patel answered
To find the values of x and y in the given rhombus ABCD, we need to understand the properties of a rhombus. A rhombus is a quadrilateral with all sides of equal length.

- The diagonals of a rhombus bisect each other at right angles. This means that the diagonals intersect at a 90-degree angle.
- The diagonals of a rhombus divide it into four congruent triangles.
- The opposite angles in a rhombus are equal.

Given these properties, let's solve for x and y.

First, let's consider the diagonals of the rhombus. Let the intersection point of the diagonals be O.

- The diagonals AC and BD bisect each other at right angles, so angle AOC and angle BOD are right angles.

Since the diagonals divide the rhombus into congruent triangles, we can focus on one of these triangles, such as triangle AOB.

- In triangle AOB, angle AOB is equal to 90 degrees (as it is a right angle).
- The opposite angles in a rhombus are equal, so angle AOB is also equal to angle ABO.

Since the sum of angles in a triangle is 180 degrees, we can write the following equation:

angle AOB + angle ABO + angle BAO = 180 degrees

We know that angle AOB = 90 degrees, and angle AOB = angle ABO, so we can rewrite the equation as:

90 degrees + angle AOB + angle BAO = 180 degrees

Simplifying further, we get:

2 * angle AOB + angle BAO = 180 degrees

Since angle AOB = angle ABO, we can substitute angle AOB with x and angle BAO with y:

2x + y = 180 degrees

Now, let's consider the fact that opposite angles in a rhombus are equal. Since angle AOC is a right angle, angle AOD is also a right angle.

- The sum of angles in a triangle is 180 degrees, so we can write:

angle AOD + angle ADO + angle OAD = 180 degrees

Since angle AOD = 90 degrees and angle ADO = angle OAD, we can rewrite the equation as:

90 degrees + angle ADO + angle OAD = 180 degrees

Simplifying further, we get:

2 * angle ADO + angle OAD = 180 degrees

Substituting angle ADO with x and angle OAD with y, we get:

2x + y = 180 degrees

This equation is the same as the one we obtained earlier. Therefore, we can conclude that x = y.

Now, let's consider the fact that the diagonals of a rhombus bisect each other at right angles. This means that the diagonals AC and BD are perpendicular.

Since opposite sides of a rhombus are parallel, the diagonals bisect each other into two congruent right-angled triangles. In each of these triangles, the sum of angles is 180 degrees. Therefore, we can write:

angle ADC + angle ACB + angle CDB = 180 degrees

Since angle ADC = angle ACB (as opposite angles are equal), we can rewrite the equation as:

2 * angle ADC + angle CDB = 180 degrees

Substituting angle ADC with x and

Consecutive angles of a Parallelogram are
  • a)
    Supplementary
  • b)
    Acute
  • c)
    Complementary
  • d)
    Equal
Correct answer is option 'A'. Can you explain this answer?

Suhani Kumari answered
Option A (supplementary)As one of the basic properties of parallelograms is that any pair of consecutive angles are supplementary.

A cyclic quadrilateral is such that two of its adjacent angles are divisible by 6 and 10 respectively. One of the remaining angles will necessarily be divisible by:
  • a)
    3
  • b)
    4
  • c)
    8
  • d)
    None of these
Correct answer is option 'D'. Can you explain this answer?

Palak Bose answered
We know that the sum of the opposite angles of a cyclic quadrilateral is 180 degrees. Let the four angles be A, B, C, and D, with A and B being the angles divisible by 6 and 10, respectively.

Since A is divisible by 6 and B is divisible by 10, we know that A = 6m and B = 10n for some integers m and n.

Now, consider the opposite angles. Since the sum of opposite angles is 180 degrees, we have:

C = 180 - B = 180 - 10n
D = 180 - A = 180 - 6m

We want to find which of the given options the angles C or D are necessarily divisible by. Let's examine each option:

1. 3: Since B is divisible by 10, it is possible that B is divisible by 5 but not 3 (e.g. B = 10). In this case, C = 180 - B would not be divisible by 3. Also, A is divisible by 6, so A is always divisible by 3, which means D = 180 - A would never be divisible by 3. So, this option is incorrect.

2. 4: Since A is divisible by 6, it is possible that A is divisible by 2 but not 4 (e.g. A = 6). In this case, D = 180 - A would not be divisible by 4. Also, B is divisible by 10, so B is always divisible by 2, which means C = 180 - B would never be divisible by 4. So, this option is also incorrect.

3. 8: If A is divisible by 6, then it can be even or odd multiples of 6 (e.g. A = 6, 12, 18, ...). D will be 180 - A, which means D can be both even and odd (e.g. D = 180 - 6 = 174, D = 180 - 12 = 168, D = 180 - 18 = 162, ...). Since D can be both even and odd, it is not necessarily divisible by 8. Similarly, C can also be both even and odd, so it is not necessarily divisible by 8. Thus, this option is also incorrect.

4. None of these: Since none of the previous options work, the correct answer is None of these.

So, the correct answer is option 4: None of these.

Four horses are tethered at four comers of a square plot of side 14 m so that the adjacent horses can just reach one another. There is a small circular pond of area 20 m2 at the centre. Find the ungrazed area.
  • a)
    42 m2
  • b)
    22 m2
  • c)
    84 m2
  • d)
    168 m2
Correct answer is option 'B'. Can you explain this answer?

Preeti Khanna answered
Total area of plot = 14 * 14 = 196m2
Horses can graze in quarter circle of radius = 7m
Grazed area = 4 * (pie r2)/4 = 154 m2
Area of plot when horses cannot reach = (196 - 154) = 42m2
Ungrazed area = 42 - 20 = 22m2

The ratio of the sides of Δ ABC is 1:2:4. What is the ratio of the altitudes drawn onto these sides?
  • a)
    4:2:1
  • b)
    1:2:4
  • c)
    1:4:16
  • d)
    None of these
Correct answer is option 'D'. Can you explain this answer?

Aakash Giery answered
Sum of any two sides should be greater than third side.
here 1+2=3 is not less than 4 ,
1+2<4 ,so="" triangle="" is="" not="" possible.="" ,so="" triangle="" is="" not="">

Given a triangular prism, then what can we conclude about the lateral faces?
  • a)
    Faces are rectangle
  • b)
    Faces are Trapezium
  • c)
    Faces are Prism
  • d)
    both rectangles Faces are Parallelogram
Correct answer is option 'D'. Can you explain this answer?

Sarita Reddy answered
In a triangular prism, the bases are triangles and the lateral faces are parallelograms.
Thus it can be both rectangles and parallelograms.
So, option (D) is correct.
If the faces are rectangles, then we call it as right triangular prism
Observe the following figure.
It is clear that the faces of the above figure are rectangles and hence it is right triangular prism.

D, E, F are the mid points of the sides BC, CA and AB respectively of ΔABC. Then ΔDEF is congruent to triangle
  • a)
    ABC
  • b)
    AEF
  • c)
    BFD, CDE
  • d)
    AFE, BFD, CDE
Correct answer is option 'D'. Can you explain this answer?

Eesha Bhat answered
The correct option is Option D.
Given : D, E and F are tge mid-point of the sides BC, CA and AB respectively of Δ ABC.
To prove : Δ DEF is congruent to traingle
Proof : 
Since E and F are midpoints of AC and AB. 
BC II FE and FE = ½ BC = BD (By mid point theorem)
BD II FE and BD = FE 
Similarly, BF II DE and BF = DE
Hence, BDEF is a parallelogram (A pair of opposite sides are equal and parallel)
Similarly, we can prove that FDCE and AFDE are also parallelograms. 
Now, BDEF is a parallelogram so it's diagonal FD divides it into two traingles of equal areas. 
Therefore, ar(Δ BDF) = ar(Δ DEF).......... (i)
In parallelogram AFDE, 
ar(Δ AFE) = ar(Δ DEF)   (EF is a diagonal)......... (ii)
In parallelogram FDCE, 
ar(Δ CDE) = ar(Δ DEF)   (DE is a diagonal)...........(iii)
From (i), (ii) and (iii)
ar(Δ BDF) = ar(Δ AFE) = ar(Δ CDE) = ar(Δ DEF)..........(iv)
If area of traingles are equal then they are congruent.
Hence, Δ DEF is congruent to triangle Δ BDF = Δ AFE = Δ CDE.

In an equilateral triangle, the incentre, circumcentre, orthocentre and centroid are:
  • a)
    concylic
  • b)
    coincident
  • c)
    collinear
  • d)
    none of these
Correct answer is option 'B'. Can you explain this answer?

Gaurav Kumar answered
The centroid is the intersection of the three medians while the incentre is the intersection of the three (internal) angle bisectors. In an equilateral triangle, each median is also an angle bisector (and vice versa), the centroid coincides with the incentre. In fact, the centroid, incentre, circumcentre and orthocentre of an equilateral triangle are coincide at the same point.

The area of similar triangles, ABC and DEF are 144cm2 and 81 cm2 respectively. If the longest side of the larger △ABC be 36 cm, then the longest side of the smaller △DEF is:
  • a)
    27 cm 
  • b)
    26 cm
  • c)
    29 cm 
  • d)
    30 cm
Correct answer is option 'A'. Can you explain this answer?

Aarav Sharma answered
Given:
- The area of triangle ABC is 144 cm^2.
- The area of triangle DEF is 81 cm^2.
- The longest side of triangle ABC is 36 cm.

To find:
- The length of the longest side of triangle DEF.

Explanation:

Step 1: Finding the Scale Factor
- The area of a triangle is given by the formula: Area = (1/2) * base * height.
- Since the triangles ABC and DEF are similar, their areas are proportional to the square of their corresponding sides.
- Therefore, we can write: (AB/DE)^2 = Area of ABC/Area of DEF.

- Substituting the given values, we get: (AB/DE)^2 = 144/81.

- Simplifying the equation, we have: (AB/DE)^2 = 16/9.

- Taking the square root of both sides, we get: AB/DE = √(16/9).

- Simplifying further, we have: AB/DE = 4/3.

- This ratio represents the scale factor between the two triangles.

Step 2: Finding the Length of the Longest Side of Triangle DEF
- The longest side of triangle ABC is given as 36 cm.

- Using the scale factor, we can write: AB/DE = 4/3.

- Substituting the values, we have: 36/DE = 4/3.

- Cross-multiplying, we get: 4DE = 36 * 3.

- Simplifying the equation, we have: 4DE = 108.

- Dividing both sides by 4, we get: DE = 27.

- Therefore, the length of the longest side of triangle DEF is 27 cm.

Conclusion:
- The length of the longest side of triangle DEF is 27 cm.
- Hence, the correct answer is option A.

The length of each side of a rhombus is 10cm and one of its diagonal is of length 16cm. The Length of the other Diagonal is:
  • a)
    5cm
  • b)
    12cm
  • c)
    13cm
  • d)
    6cm
Correct answer is option 'B'. Can you explain this answer?

Abhishek Kumar answered
Visualise a rhombus of each side 10 cm. Now, we know that the diagonals of a rhombus are perpendicular bisectors i.e it is perpendicular to each other and divide each diagonal into two parts since there are two diagonal so there will be four parts out of which two parts of the same diagonal are equal . So the diagonal of length 16cm is divided into two parts each of 8 cm Since two diagonal are perpendicular bisectors of each other so it will divide the rhombus into four equal right angled triangle visualising one triangle we get: Hypotenuse =side of rhombus =10cm one side whose measure os unknown =x (say) another side =8 cm. Applying phythogorus theorem hypotenuse ² = base² (one side)+ perpendicular² or, hypotenuse²-base² =perpendicular ² 10² - 8²= perpendicular² 100-64 = perpendicular ² 36=perpendicular ² 6²=perpendicular ² 6=perpendicular since diagonal is divided into two parts total length of one diagonal =2×perpendular. =2×6=12cm

The Diagonals AC and BD of a Parallelogram ABCD intersect each other at the point O such that ∠DAC = 30 and ∠AOB = 70. Then, ∠DBC?
  • a)
    30
  • b)
    45
  • c)
    35
  • d)
    40
Correct answer is option 'D'. Can you explain this answer?

AO = 5, OC = 7, and OD = 9. Find the length of OB.

We know that in a parallelogram, opposite sides are equal in length, so AB = CD and BC = AD. Let x be the length of OB.

By the properties of diagonals in parallelograms, we know that AO/OC = BO/OD. Substituting the given values, we have:

5/7 = x/9

Solving for x, we get:

x = 9(5/7) = 6.43 (rounded to two decimal places)

Therefore, the length of OB is approximately 6.43 units.

Chapter doubts & questions for Geometry - Mathematics & Pedagogy Paper 2 for CTET & TET Exams 2024 is part of CTET & State TET exam preparation. The chapters have been prepared according to the CTET & State TET exam syllabus. The Chapter doubts & questions, notes, tests & MCQs are made for CTET & State TET 2024 Exam. Find important definitions, questions, notes, meanings, examples, exercises, MCQs and online tests here.

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