Hello there!
Surface Area = 4pir^2
First, we need to find our radius, since we have our diameter all we need to do is divide it by 2. That means, 10 divided by 2 equals 5.
Our radius is 5.
Now, we can plug it into the formula.
4(3.14)(5^2)
4(3.14)(25)
4(78.5)
4(78.5) = 314
Now, convert into pi.
314 = 100pi or 100Π
