In an isosceles triangle ABC with base AC, the sum of the angles A and C is 156 * Find the angles of triangle ABC.

Since the angles A and C are at the base of the AC, they are equal, we denote them as x:
x + x = 156.
Let’s solve the equation and find the value of x:
2x = 156;
x = 156/2;
x = 78 degrees.
Angle A = Angle C = 78 degrees.
In the triangle ABC, two angles A and C are known. Find the angle B. By the theorem on the sum of the angles of a triangle: the sum of all interior angles of any triangle is 180 degrees, then:
angle A + angle B + angle C = 180 degrees;
78 + angle B + 78 = 180;
angle B = 180 – 156;
angle B = 24 degrees.
Answer: angle A = 78 degrees, angle B = 24 degrees, angle C = 78 degrees.