Question

if one side of triangle is 1/4 of its perimeter, other side is 7 cm and third side is 2/5 of its perimeter, then find the perimeter of the triangle

Answer 1

Define x:

Let the perimeter be x

Express the length in term of x:

Side 1 = x/4

Side 2 = 7 cm

Side 3 = 2x/5

Form equation and solve x:

x/4 + 7 + 2x/5 = x

x - x/4 - 2x/5 = 7

7/20 x = 7

x = 7 ÷ 7/20

x = 25 cm

Answer: The perimeter is 25 cm

Answer 2

Let the perimeter of triangle be x

Length of first side = a = 1/4x

Second side = b = 7 cm

Third side = c = 3/5x

Perimeter of triangle = x = a+b+c

1/4x + 7 + 2/5x = x

7 = x - 1/4x -2/5x

7 = 20x-5x-8x/20

7*20 = 20x-13x

7x =140

x = 140/7

x = 20

I Hope It Helps You!