How to find the angles of an isosceles triangle if one angle is 130 degrees?

An isosceles triangle is a triangle in which the sides are equal.

Since the angles at the base are equal in an isosceles triangle, only the angle at the apex can be an obtuse angle. The angles at the base of an isosceles triangle are always sharp.

Since the sum of all the angles of the triangle is 180º, the angles at the base are equal:

∠А = ∠С = (180º – ∠В) / 2;

∠А = ∠С = (180º – 130º) / 2 = 50º / 2 = 25º.

Answer: the angles at the base ∠А and ∠С are equal to 25º, the angle at the apex ∠B is equal to 130º.