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All questions of Achievers Section: Section 3 (HOTs) for Class 9 Exam

Read the given statements carefully and state ‘T’ for true and ‘F’ for false.
(i) The sum of the angles in any quadrilateral is 360 degrees.
(ii) A triangle can have more than one obtuse angle.
(iii) The diagonals of a parallelogram bisect each other.
  • a)
    (i)-T, (ii)-F, (iii)-T
  • b)
    (i)-F, (ii)-F, (iii)-T
  • c)
    (i)-T, (ii)-T, (iii)-F
  • d)
    (i)-T, (ii)-F, (iii)-F
Correct answer is option 'A'. Can you explain this answer?

Understanding the Statements
To determine the truth value of each statement, let's analyze them one by one.

Statement (i): The sum of the angles in any quadrilateral is 360 degrees.
- This statement is **True**.
- In any quadrilateral, the interior angles add up to 360 degrees. This can be derived from the fact that a quadrilateral can be divided into two triangles, each having a total angle sum of 180 degrees (180 + 180 = 360).

Statement (ii): A triangle can have more than one obtuse angle.
- This statement is **False**.
- A triangle can have only one obtuse angle (greater than 90 degrees) because the sum of all angles in a triangle is 180 degrees. If there were two obtuse angles, their sum would exceed 180 degrees, which is impossible in a triangle.

Statement (iii): The diagonals of a parallelogram bisect each other.
- This statement is **True**.
- In a parallelogram, the diagonals do indeed bisect each other, meaning they cut each other into two equal parts. This property is a defining characteristic of parallelograms.

Conclusion
Based on the analysis:
- (i) is True (T)
- (ii) is False (F)
- (iii) is True (T)
Thus, the correct answer is option 'A': (i) - T, (ii) - F, (iii) - T.

Read the following statements carefully and select the correct option.
Statement-I: The measure of each interior angle of a regular octagon is 135 degrees.
Statement-II: The measure of each exterior angle of a regular octagon is 45 degrees.
  • a)
    Statement-I is true but Statement-II is false.
  • b)
    Statement-I is false but Statement-II is true.
  • c)
    Both Statement-I and Statement-II are true.
  • d)
    Both Statement-I and Statement-II are false.
Correct answer is option 'C'. Can you explain this answer?

EduRev Class 9 answered
First, let's calculate the interior angle of a regular octagon.
A regular polygon with n sides has an interior angle given by the formula:
For a regular octagon (n=8):
So, Statement-I is true.
Next, let's calculate the exterior angle of a regular octagon.
The exterior angle of a regular polygon is given by the formula:
So, Statement-II is also true.
Therefore, both Statement-I and Statement-II are true.
Hence, the correct option is:C

Read the following statements carefully and select the correct option.
Statement-I: A parallelogram with all sides equal and diagonals intersecting at right angles is a square.
Statement-II: All squares are rectangles, but not all rectangles are squares.
  • a)
    Statement-I is true but Statement-II is false.
  • b)
    Statement-I is false but Statement-II is true.
  • c)
    Both Statement-I and Statement-II are true.
  • d)
    Both Statement-I and Statement-II are false.
Correct answer is option 'B'. Can you explain this answer?

Let's Tute answered
A parallelogram with all sides equal and diagonals intersecting at right angles is actually a rhombus, not necessarily a square, making Statement-I false. All squares are rectangles because they have all the properties of rectangles (opposite sides equal and all angles right angles), but not all rectangles are squares because they may not have all sides equal, making Statement-II true.

Match Column I with Column II and select the correct option.
  • a)
    P-2, Q-4, R-3, S-1
  • b)
    P-1, Q-2, R-3, S-4
  • c)
    P-4, Q-3, R-2, S-1
  • d)
    P-1, Q-4, R-3, S-2
Correct answer is option 'B'. Can you explain this answer?

EduRev Class 9 answered
P. Mean of {2, 4, 6, 8, 10} = (2+4+6+8+10)/5=6.
Q. Median is the middle value, which is 6.
R. Mode is the most frequent value, which is 5.
S. Range = maximum - minimum = 10 - 2 = 8.

Match Column I with Column II and select the correct option.
  • a)
    P-1, Q-3, R-2, S-4
  • b)
    P-4, Q-1, R-3, S-2
  • c)
    P-1, Q-4, R-3, S-2
  • d)
    P-2, Q-4, R-1, S-3
Correct answer is option 'C'. Can you explain this answer?

Imk Pathshala answered
P. Let the number be x. Then,  3x+5=17 gives 3x=12 sox=4.
Q. The sum of the angles in a triangle is always 180°.
R. Perimeter of rectangle = 2(length+width)=2(6+4)=20.
S. Let the numbers be  x and  y.  x+y=15 and  x−y=5. Solving, x=10,  y=5.

Match Column I with Column II and select the correct option.
  • a)
    P-2, Q-3, R-1, S-4
  • b)
    P-4, Q-1, R-3, S-2
  • c)
    P-2, Q-3, R-4, S-1
  • d)
    P-1, Q-4, R-3, S-2
Correct answer is option 'A'. Can you explain this answer?

Imk Pathshala answered
P. Area of a circle
Q. The median is the middle value, which is 9.
R. The mode is the most frequent value, which is 7.
S. Sum of first 5 natural numbers = 1+2+3+4+5=15.

Match Column I with Column II and select the correct option.
  • a)
    P-3, Q-2, R-4, S-1
  • b)
    P-1, Q-2, R-3, S-4
  • c)
    P-1, Q-4, R-2, S-3
  • d)
    P-2, Q-1, R-3, S-4
Correct answer is option 'B'. Can you explain this answer?

EduRev Class 9 answered
P. Derivative of x2  is 2x.
Q. Integral of 1 is  x+c
R. Slope of the line y=3x+4 is the coefficient of x, which is 3.
S. Value of π to two decimal places is 3.14.

Match Column I with Column II and select the correct option.
  • a)
    P-1, Q-2, R-3, S-4
  • b)
    P-2, Q-3, R-1, S-4
  • c)
    P-1, Q-4, R-2, S-3
  • d)
    P-3, Q-1, R-2, S-4
Correct answer is option 'A'. Can you explain this answer?

Let's Tute answered
P. First 4 prime numbers are 2, 3, 5, and 7. Sum = 17.
Q. Probability of heads in a fair coin = 1/2.
R. A tetrahedron has 6 edges.
S. Sum of interior angles of a polygon with  n sides = (n-2) x 180º,for hexagon  n = 6, so 4 x 180º = 720º

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