Find the sides of an isosceles triangle if its perimeter is 64cm and the midline parallel to the base is 11cm.

We will solve this task in steps and explain each of them in detail.

1) 11 * 2 = 22 centimeters – the length of the base of an isosceles triangle, since the middle line parallel to the base is 11 centimeters;

2) 64 – 22 = 42 centimeters – the sum of the lengths of the sides, since the perimeter of an isosceles triangle is 64 centimeters, and the length of the base is 22 centimeters;

3) 42: 2 = 21 centimeters – the length of the side, since the sum of the sides is 42 centimeters, and they are equal to each other.

Answer: 21 centimeters.