Angle A of an isosceles trapezium is 115° ; find the angles B, C and D.
Answers:
Since, the base angles of an isosceles
trapezium are equal,
∴ ∠A = ∠B = 115°
Also, ∠A and ∠D are co-interior angles
and their sum = 180°
∴ ∠A + ∠D = 180°
⇒ 115° + ∠D = 180°
⇒ ∠D = 180° – 115°
⇒ ∠D = 65°
Also, ∠D = ∠C = 65°
∴ ∠B = 115°, ∠C = 65° and ∠D = 65°