The sum of the two sides of the triangle is 85 cm and the length of the third side is 80% of this sum. Calculate the perimeter.

1) Let’s find out what is the length of the third side, if it is known that it is 80% of the sum of the other two sides of the triangle, and the sum of the other two sides is 85 cm.

85 – 100%

X – 80%;

X = 85 * 80/100;

X = 68 cm.

2) Find the perimeter of this triangle if it is known that the sum of the first two sides is 85 cm, and the third side of the triangle is 68 cm long.

85 + 68 = 153 cm.

Answer: the perimeter of this triangle was 153 cm.