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Understanding Quadrilaterals — Class 8 CBSE Mathematics MCQs with Solutions
Free Class 8 CBSE Mathematics Understanding Quadrilaterals MCQs with step-by-step solutions. Practise online on Prepizo — no login needed.
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Sample questions with solutions
Q1 — easy
How many sides does a pentagon have?
A. 4
B. 5 ✓ Correct
C. 6
D. 7
Solution: Penta means five.
Q2 — easy
In a parallelogram, opposite angles are:
A. equal ✓ Correct
B. supplementary
C. complementary
D. unrelated
Solution: Opposite angles of a parallelogram are equal.
Q3 — easy
A rhombus is a parallelogram in which:
A. all angles are 90°
B. all sides are equal ✓ Correct
C. diagonals are equal
D. only one pair of sides is parallel
Solution: A rhombus has four equal sides.
Q4 — hard
In a rhombus, one diagonal is 16 cm and the other is 12 cm. Find its side length.
A. 8 cm
B. 10 cm ✓ Correct
C. 14 cm
D. 20 cm
Solution: Half-diagonals 8 and 6; side = √(64+36) = 10 cm.
Q5 — hard
ABCD is a parallelogram where ∠A = (3x − 10)° and ∠C = (2x + 30)°. Find x.
A. 30
B. 40 ✓ Correct
C. 50
D. 60
Solution: Opposite angles equal: 3x − 10 = 2x + 30 → x = 40.
Q6 — hard
How many diagonals does a regular octagon have?
A. 16
B. 18
C. 20 ✓ Correct
D. 24
Solution: n(n−3)/2 = 8 × 5 / 2 = 20.
Q7 — medium
Each exterior angle of a regular polygon is 45°. How many sides has it?
A. 6
B. 8 ✓ Correct
C. 9
D. 10
Solution: 360 ÷ 45 = 8.
Q8 — medium
In a parallelogram ABCD, ∠A = 70°. Find ∠B.
A. 70°
B. 90°
C. 110° ✓ Correct
D. 140°
Solution: Adjacent angles are supplementary: 180 − 70 = 110°.
Q9 — medium
The diagonals of which quadrilateral bisect each other at right angles?
A. trapezium
B. rhombus ✓ Correct
C. kite
D. scalene quadrilateral
Solution: A rhombus has perpendicular bisecting diagonals.