Question

The formula for the surface area of a circular cylinder is SA = 2πr 2 + 2πrh cubic units. What do 2πr 2 and 2πrh represent?

Answer 1

remember
area=pir^2
circumference=2pir

the surface aera if you thinkg about it is
2 times the tops+area around

the tops are circles so 2*pir^2 is tops

the area around is a rectangle that has been wrapped around the cylinder,
the hieght is the legnth and the circumference is width
so 2hpir is the area around

2pir^2 is the areas of the tops
2hpir is the area around