Equation: <em />
diameter is twice the radius.
2.5^2=6.25
6.25 π ≈19.625
5 π ≈15.70
15.70*2=31.4
31.4+19.625=51.025cm^2
Answer:
Decreased by 40%!
Step-by-step explanation:
At first it goes down by 10%, then 30%, so you just add them together and get decreased by 40%.