Question

In triangle ABC , AB= BC and angle B = 80°,then find angle A.

Answer 1

Since , angles opposite to equal sides of a ∆ are equal.

→<A=<C = x (say)

Now,

By angle sum property of ∆ , we get

2x + 80= 180

→ 2x =100

→ x =50

Thus,

<A = 50

Answer 2

Then the length of the angle is obviously 80°