Practice Questions: Understanding Elementary Shapes

Q1: The sum of angles of a quadrilateral is _______.
Ans: 360^∘

Q2: The diagonals of an isosceles trapezium are ______.
Ans: Equal

Q3: A sphere has _____ vertex and 0 edges.
Ans: Zero

Q4: Cube and cuboid have an equal number of faces, vertices and edges. Say True or False.
Ans: True

Q5: A triangular pyramid is called a ______.
Ans: Tetrahedron

Q6: 1 mm = ____ cm
Ans: 0.1

Q7: Instrument used to measure angle is called_____.
Ans: Protractor

Q8: Standard unit for measuring an angle is called ______ and is denoted by ______.
Ans: degree, ∘

Q9: 90.5^∘ is called ____ angle.
Ans: Obtuse

Q10: 177^∘ is called _____ angle.
Ans: Obtuse

Q11: Name the solid objects for each of the 3D shape
(a) cone
(b) cylinder
(c) cube 
Ans: (a) Party hats, oil funnel, Ice cream cone
(b) Coke can, gas cylinder, electric cells
(c) Rubix, dice, sugar and ice cubes

Q12: What is the condition for two triangles to be congruent?
Ans: Two triangles are said to be congruent if the corresponding sides and angles of both triangles are equal to each other.

Q13: What is the perimeter of a triangle?
Ans: The sum of all three sides of a triangle is called the perimeter of a triangle.

Q14: How many degrees are there in between the clock hands when it displays 7′0 clock?
Ans:
It is 30^∘ between any two numbers on the clock.
So, there are 7 divisions between 12 and 7.
Thus, total degrees = 7 × 30^∘ = 210^∘.

Q15: How many degrees are there in    
(a) four right angles
(b) right angles
Ans: (a) four right angles = 4 × 90^∘ = 360^∘.
(b)