Question

In the given figure BD = BC, find the value of x

Answer 1

Given that BD = BC

∆BDC is on isosceles triangle.

In isosceles triangle, angles opposite to equal sides are equal.

∠BDC = ∠BCD  ...(1)

Also ∠BCD + ∠BCX = 180°  ...[∵ Liner Pair]

∠BCD + 115° = 180°

∠BCD = 180° – 115°

∠BCD = 65°  ...[By (1)]

In ∆ADB

∠BAD + ∠ADB = ∠BDC ...[∵ BDC is the exterior angle and ∠BAD and ∠ABD are interior opposite angles]

35° + x = 65°

x = 65° – 35°

x = 30°