A square patio has an area of 122 square feet. How long is each side of the patio to the nearest 0.05?

Iam trying to solve a linear equation for the shoe size of someone 84" tall taking into consideration example 1 is 69" tall with a shoe size of 9 and example 2 is 72 inches tall with a shoe size of 11. i understand that the equation should be y=mx+b and that on the graph the answer is (3,2) but i just don't understand how to create the equation to solve for 84-inches and 60-inches tall questions. after two days, i need .

Icould really use some with this question.

What is the image of c for a 90° counterclockwise rotation about a? (3, 7) (-1, 3) (7, 3)