Question

if angle A is 100 degree and triangle ABC is isosceles find the exterior angle at C​

Answer 1

Answer:

140°

Step-by-step explanation:

It is an isosceles triangle so 2 sides are equal.

since a=100° and a triangle is of 180°

therefore b=c=40°

angle c being on a straight line has 180° by angle sum property.

we know angle c=40°

there the exterior angle at c=180°-40°=140°

Answer 2

Answer:

Step-by-step explanation:
∠A = 100°
∠B = ∠C
By Angle Sum Property (ASP)
∠A + ∠B + ∠C = 180°
100° + ∠B + ∠C = 180°
x + x = 180° - 100°
2x = 80°
x = 80° / 2
x = 40°

∠B=40°
∠C=40°