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.

 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

step-by-step explanation:

1. practice, practice & more practice

2. review errors

3. master the key concepts

do not try to memorise the processes.

4. understand your doubts.

5. create a distraction free study environment

6. create a mathematical dictionary

7. apply maths to real world problems.