Question

Please help!!! Use an algebraic equation to solve the problem. The sides of a triangle are in the ratio 3 : 4 : 5. What is the length of each side if the perimeter of the triangle is 90 cm?

A. 22.5 cm, 30 cm, and 37.5 cm
B. 7.5 cm, 11.5 cm, and 32.1 cm
C. 10.5 cm, 11.5 cm, and 12.5 cm
D. 19.3 cm, 25.7 cm, and 32.1 cm

Answer 1

3:4:5.....added = 12

3/12(90) = 270/12 = 22.5
4/12(90) = 360/12 = 30
5/12(90) = 450/12 = 37.5

looks like it is gonna be A

Answer 2

A. 22.5 cm, 30 cm and 37.5 cm

Explanation:

To find the perimeter of a triangle, all the sides are added together:

A + B + C = Perimeter

Knowing the ratio of the sides, all the sides can be multiplied by a common factor, for the ratio to stay the same. Adding up these factors, setting it equal to a perimeter of 90, and solving:

3x + 4x +5x = 90

12x = 90

x = 7.5 cm

Side Lengths

• 3 * 7.5 = 22.5 cm
• 4 * 7.5 = 30 cm
• 5 * 7.5 = 37.5 cm