Question

A right cylinder has a radius of 3 and a height of 12. What is its surface area?

Answer 1

Answer:

90π units²

Step-by-step explanation:

(refer to attached)

Total Surface are off a right cylinder = area of its ends + area of curved surface

Given radius, r = 3 units and height, h = 12 units

Area of 2 ends,

= Area of 2 circles

= 2 x πr²

= 2π (3²)

= 2π (9)

=18π units²

Area of curved surface,

= 2πrh

= 2π(3)(12)

= 72π units²

Hence,

Surface area = 18π + 72π = 90π units²