Question

In the given figure, ∆ABC is an isosceles triangle where AB=AC and angle ABC=50°. Find angle BDC.

Answer 1

Given ABC is isosceles
AB = AC
angle ABC = 50
so
ACB = 50 (opposite angles of equal sides are equal)
Now, in ABC
angle (A+B+C)= 180
internal angle sum property
100 + angle A = 180
angle BAC= 180-100
angle BAC= 80
angle B AC= angle BDC
angle made by same arc are equal. So
angle BDC = 80

Answer 2

Hey!! Here is your Answer:

In ∆ABC, AB=AC

angle ABC=50°

•: angle ACB=50°(if two sides of a ∆ are equal then the opp. angles are equal)

Now in ∆ABC,

=> angle(A+B+C) =180°

=> angleA+50°+50°=180°

=> angleA+100°=180°

=> angleA=180°-100°

=> angleA=80°

=> As ∆BDC lie on the same base

•: angle BDC=80°

Hope it helps you!!