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25 votes
25 votes
This composite figure is made of three identical cylinders that are connected together

Radius:3 Height:8

User Imp
by
2.7k points

1 Answer

19 votes
19 votes
The surface are of a cylinder is

SA = 2πr2 + 2πrh

where:
r = radius
h = height

This formula comes from adding the areas of the surfaces of the cylinder. It has two flat circular faces and a rounded face.

If we cut the cylinder from the circular face symmetrically, the surface area for one piece will be

SA = 2[(πr2)/2] + (2πr/2)h + 2rh

We will have 2-half flat circular faces, a flat rectangular surface, and half of the rounded surface.

Simplify the SA formula.

SA = πr2 + πrh + 2rh
SA = r(πr + πh + 2h)

Substitute the values into this formula.

SA = 3(3π + 8π + (2*8))
SA = 3(11π + 16)
SA = 33π + 48
SA = 151.67 cm2

Since we have 2 pieces, multiply this result by 2.

2(151.67 cm2) = 303.34 cm2.

The total area is 303.34 cm2.
User JGWeissman
by
2.7k points
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