You can
put this solution on YOUR website!let the shoeter side be x
x*(x+4) = 45
x^2 + 4x = 45
x^2 + 4x - 45 = 0
Now we can use the qyradratic formula

x = -18/2 or 10/2
x = -9 or 5
Since length of anyhting can not be a negative number, 5 is the length of the short side and 5+4 = 9 will be the longer length of the table
The dimension of the table tennis table is 5ft*9ft