Question

The side of a triangle with 3 equal sides is 7 inches shorter than the side of a square. The perimeter of the square is 39 inches more than the perimeter of the triangle. Find the length of a side of the square.

Answer 1

 length of  square = 18

x = side of square

x-7 = side of triangle

3(x-7) + 39 = 4x

3x-21 + 39 = 4x

3x+18 = 4x

18=x

square    18x4 =72(perimeter square)

triangle side  (18-7=11)

11x3 = 33(perimeter triangle) 

72-33=39