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A cylinder has a surface area of 80π in2. The radius is 4 inches. Find the height.

User Skfp
by
4.6k points

2 Answers

1 vote

Answer:

6 in

Explanation:

80π = 2πr × (r+h)

80π = 2π ×4 × (4+h)

4 + h = 10

h = 6

User Msonic
by
5.4k points
3 votes

Answer:

The height is 6 inches

Explanation:

The surface area of a cylinder is given by

SA = 2 pi r^2 + 2 pi rh where r is the radius and h is the height

Substituting what we know

80pi = 2 pi (4)^2 + 2 pi *4 *h

80pi = 32 pi + 8 pi h

Divide each side by pi

80 = 32 + 8 h

Subtract 32 from each side

80-32 = 8h

48 = 8h

Divide each side by 8

6 =h