The sides of a triangle are 5: 7: 11, and the sum of the largest and smallest sides is 80 cm.

The sides of a triangle are 5: 7: 11, and the sum of the largest and smallest sides is 80 cm. Calculate the perimeter of the triangle.

The solution of the problem:
1. Find out what the sum of the largest and smallest numbers in relation to the sides of the triangle is equal to.
5 + 11 = 16.
2. Determine how many centimeters are in one part.
80/16 = 5 centimeters.
3. What is one side of the triangle?
5 * 5 = 25 cm.
4. What is the other side of the triangle.
5 * 7 = 35 cm.
5. What is the third side of the triangle.
5 * 11 = 55 cm.
6. Let’s calculate what the perimeter of the triangle is.
25 + 35 + 55 = 105 cm.
Answer: The perimeter of a triangle is one hundred and five centimeters.