Amount Required

[Guest]

A closed cylinder has the following specifications :

Base : 7 ft.

Height : 12 ft. 6 in.

Determine amount of metal needed to produce the cylinder.

Not sure how to solve.

[Guest]

The total surface area A of a closed cylinder is given by the formula:
$A=2\pi rh+2\pi r^2$


12 feet 6 inches = $12+\frac{6}{12}=12.5$ feet

$r=\frac72=3.5$ feet

[Guest]

Thanks.

Check my calculations :

Surface area : 2 pi r h + 2 pi r^2

2 * 3.1416 * 3.5 * 12.5 + 2 * 3.1416 * 3.5 * 3.5

2748.9 + 76.96 = 2825.8 = 2826. Would that be sq. ft. ?

[Guest]

I get 351.68

[Guest]

I rechecked:

Decimal is in wrong place and one extra number with pi

274.89 + 76.96 = 351.85