Help me to do this question plz plz plz I will mark you as brainlist

This is set question
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How do you find the circumfrance of a circle?

When solving this problem: 3025/5.5 = a/90.75 you get 49912.5 which would be the length of one of the sides of a square when the area is only 90.75 inches. is that answer correct, why, and how is it possible?

If each bricks costs and he can only buy one brick how much will it cost him to get the material to put around the outside of his garden?