You were on the right track for 11. You just needed to find the square root of 9 which is 3. And for 15 you square both sides and the answer would just be the square root of 77 since it's not a perfect square and it can't be broken down anymore.
The formular for finding the area of a square is A = (a)squared Since we are finding the length of each the sides we make a the subject A = (a)squared √A =√(a)squared a = √A Given A = 9 a =√9 a =3 Therefore each side of tne photo is 3inches
15. (b)squared = 77 To make b the subject we square root both sides of the equation. √(b)squared =√77 b = 8.774964384
