The lengths of the sides of the triangle are 3, 8 and 10.
A triangle is a polygon that is made up of three sides. The sum of angles in a triangle is 180 degrees. The perimeter of a triangle is the sum of the three sides.
Let x represent the length of the third side of the triangle.
Length of the first side = x + 5
Length of the second side = x + 7
Perimeter = x + x + 5 + x + 7 = 21
In order to determine the length of the third side, solve for x in this equation: x + x + 5 + x + 7 = 21
3x + 12 = 21
3x = 21 - 12
3x = 9
x = 3
Length of the first side = x + 5 = 3 + 5 = 8
Length of the second side = x + 7 : 3 + 7 = 10
Please find attached an image of a triangle. To learn more about triangles, please check: https://brainly.com/question/25813512
