Acircle is drawn within a square as shown.

what is the best approximation for the area of the shaded region?

use 3.14 to approximate pi.

a) 21.5 cm²

b) 78.5 cm²

c) 100 cm²

d) 178.5 cm²

You use the equation 3.14r^2, for your problem, 3.14(5^2). Then you get 3.14(25) and guessing without using a calculator, you can see that it's going to be at least three times itself but not yet four. Therefore you can approximate the answer to be between 75 and 100 squared. I did this without a calculator but to get the exact answer you'd use a calculator and it would be letter B) 78.5 cm^2. Hope this helped!