Answer:
I) 616
II) 4.53
Step-by-step explanation:
For the first one, just plug in 7 as R.
A = 4 x (22/7) x 7^2
A = 12.57142857 x 49
A = 616
For the second, one, put 452 4/7 as A.
452 4/7 also is 258.285
258.285 = 4 x (22/7) x r^2
258.285 = 12.57142857 x r^2
Divide both sides by 12.57142857
20.55372408 = r^2
Square root 20.55372408 for R.
4.533621519 = R
OR
4.53 = R
