How many degrees should there be in an isosceles triangle?

In the equilateral triangle, all the sides are the same length and all the angles are the same size (congruent). Since the sum of the angles of a triangle is always 180 degrees, we can figure out the measure of the angles of an equilateral triangle.

Another Answer:-

An isosceles triangle has 2 equal base angles plus another angle and the 3 interior angles add up to 180 degrees.