Answer: 20pi,
Step-by-step explanation: 20pi, 62.8
and the diameter is 4, divide it by two, and you will get a radius of 2.
D/2=R
The next step is using the surface area formula of 4 times pi times radius squared. (4*pi*R^2) Treat Pi as a variable and do r squared which is 4, and then do 4*4 and you will get 16, then you multiply with pi and get 16pi
16pi divided by two will be a half circle. so we then get 8pi, but we're not done yet, we still have to find the bottom surface area, which is pi*R^2.
You square the radius (2) -> (4)
and will get 4pi. Add the total, 20pi.
And since it's asking for surface area without pi, simply do 20*3.14 and you will get 62.8.