If we have two values of r, r= 3.14 and r = 3, we have to substitute in the expression r^2 to solve, to solve a square number you have to multiply the number for itself:
So I looked at the graphs and the only one that actually even reaches 75 is the dotted one on the left. The one in the middle obviously doesn't go anywhere and the one on the right goes to 65, not 75.