Question

Triangle ABC is isosceles.

Triangle A B C. Angle A is x degrees, angle B is 118 degrees, angle C is x degrees. Sides A B and B C are equal.

Which equation can be used to find the degree measure of Angle A?
118 = x + x
x + x + 118 = 180
118 + 180 = x + x
(x + x) minus 118 = 180

Answer 1

x + x + 118 = 180

(Angles in a triangle sum to 180°. Solve: 2x + 118 = 180 → 2x = 62 → x = 31°.)