Question

If each of the sides of a square are lengthened by 5 ​cm, the area becomes 169 cm. Find the length of a side of the original square.

Answer 1

8 [cm].

Explanation:

1. if original length of the side is 'a', then the final length of it after lengthenening is (a+5);

2. if the final area becomes 169, then it is possible to make up the equation of the final area:

(a+5)²=169;

3. solution of the equation above is a=8. It means the initial/original length was 8.