Question

ABCD is a trapeIum ABII CD angle a = angle b = 40 degres, find angle c and d are the equal?

Answer 1

Given

• ABCD is a trapezium,
• AB║CD
• ∠A = ∠B = 40°

To find

• ∠C and ∠D

Solution

• ∠A = ∠B = 40°
• ∠B + ∠C = 180°  (Adjacent angles are supplementary)
• 40° + ∠C = 180°
• ∠C = 180° - 40°
• ∠C = 140°

☯ Measure of ∠C = 180°

• ∠A + ∠D = 180°  (Adjacent angles are supplementary)
• 40° + ∠D = 180°
• ∠D = 180° - 40°
• ∠D = 140°

☯ Measure of ∠D = 140°

✯ ∠C = ∠D = 140° ( ∴ They are equal )