The area of a square is 45 more than the perimeter. How do you find the length of the side?
1 Answer
Length of one side is 9 units.
Rather than doing a straight factorising approach I have used the formula to demonstrate its use.
Explanation:
As it is a square the length of all the sides is the same.
Let the length of 1 side be L
Let the area be A
Then
Perimeter is
The question states: "The area of a square is 45 more than.."
Substitute equation (3) into equation (1) giving:
So now we are able to write just 1 equation with 1 unknown, which is solvable.
'~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Subtract
The conditions that satisfy this equation equalling zero gives us the potential size of L
Using
Of these two
So area does indeed equal sum of sides + 45