- A62°
- B105°
- C118°
- D128°
Step-by-Step Solution
AD is a transversal of the parallel sides AB and DC, so ∠A and ∠ are co-interior angles: .
Answer: C) 118°
In trapezium ABCD, the arrow marks show AB ∥ DC. ∠A = 62° and ∠B = 75°. Find ∠D.
Class 8Understanding QuadrilateralsQuadrilaterals
Key idea: Sum of interior angles
**Sum of interior angles of any quadrilateral = 360°.**
Why? Draw one diagonal — it splits the quadrilateral into two triangles. Each triangle has angles summing to 180°. Two triangles → 360°.
More generally: for an n-sided polygon, sum of interior angles = (n − 2) × 180°. For a quadrilateral, n = 4: (4 − 2) × 180° = 360°.
Why? Draw one diagonal — it splits the quadrilateral into two triangles. Each triangle has angles summing to 180°. Two triangles → 360°.
More generally: for an n-sided polygon, sum of interior angles = (n − 2) × 180°. For a quadrilateral, n = 4: (4 − 2) × 180° = 360°.
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More Class 8 Understanding Quadrilaterals practice
A floor is tiled with identical regular hexagons with no gaps. At the orange corner…Which quadrilateral has all sides equal AND all angles equal?Which quadrilateral is defined as having at least one pair of parallel sides?In a parallelogram ABCD, ∠A = 75°. Find ∠C.Which term describes a polygon in which at least one interior angle is greater than 180°?