area of top = pi R^2
area of bottom = pi R^2
area of side = 2 pi R h
so
2 pi R^2 + 2 pi R h
= 2 pi R (R + h)
A cylinder of height 12 cm and radius 5cm is made of cardboard. Use the value of 22
7
for π to calculate the total area of cardboard needed to make:
(a) A closed cylinder
1 answer