One side of an obtuse isosceles triangle is 17 cm smaller than the other. Find the sides of this triangle if its perimeter is 77 cm.

1. Let’s say the side of an isosceles triangle is x centimeters.

2. Determine the length of its base.

(x + 17) centimeters.

3. Let’s calculate the side by making the equation.

x * 2 + x + 17 = 77;

3x = 77 – 17 = 60;

x = 60/3 = 20 centimeters.

4. Find out how many centimeters the base is.

x + 17 = 20 + 17 = 37 centimeters.

Answer: The sides are 20 centimeters each, the base is 37 centimeters.