Angle 1 is equal to angle 2 is 110 degrees. Prove triangle ABC is isosceles.

Given: triangle ABC – isosceles;
AC – base;
angle BAC = angle BCA;
angle ABC = 110 degrees
Find: angle BAC, angle BAC
Decision:
Consider an isosceles triangle ABC. The degree measure of all angles in any triangle is 180 degrees. Therefore, angle BAC + angle BCA + angle ABC = 180. If angle BAC = angle BCA and angle ABC = 110 degrees, then angle BAC + angle BAC + 110 = 180;
angle BAC + angle BAC = 180 – 110;
angle BAC + angle BAC = 70;
2 * angle BAC = 70;
angle BAC = 70: 2;
angle BAC = 35 degrees.
Answer: 35 degrees; 35 degrees.