You need to find the perimeter of the triangle which you need to find the length of each side. We are given one side length already 19 cm. We are also given 10 cm which is half of one side length. Due to the small vertical lines on the base line we know the triangle is symmetrical and we are told that the base line is cut in half making 2 equal right triangles. We are given the hypotenuse of both right triangles which is 19 cm. The perimeter of the triangle is 19+19+10+10 The perimeter is 58 cm
