2πr^2 + 2πrh.
r is the radius circle face.
h is the length/height of the cylinder.
πr^2 is the formula for circles, and there are 2 circles in a cylinder. So 2 x πr^2 would be determine the area of the 2 circles.
2πr is the formula for circumference. 2πr x h would the area of the curved face.
