If the sides of a square are lengthened by 7cm, the area becomes 121cm2. Find the length of a side of the original square.

1 answer

a=leght of side of original square
b=leght of side of new square

b=a+7
a=b-7

Area of new square is:
A=b^2=121
b=sqroot(121)=11

a=b-7=11-7=4

Length of a side of the original square is 4