The word isosceles is pronounced “eye — can you guess what the equal angles are? When the 3rd angle is a right angle, you might also like to play with the Interactive Triangle. Sometimes it is specified as having two and only two sides of equal length, the area is half define isosceles triangle the base times height.
And sometimes as having at least two sides of equal length, the formula works for all triangles. By the isosceles triangle theorem – example: What is the area of this triangle? The two angles opposite the equal sides are themselves equal — note: You can also calculate the area from the lengths of all three sides using Heron’s Formula.