Question

A company manufactures aluminum mailboxes in the shape of a box with a half-cylinder top. The company will make 1649 mailboxes this week. If each mailbox has dimensions as shown in the figure below, how many square meters of aluminum will be needed to make these mailboxes?

Answer 1

in case of cylinder SA i dont see where you halfed it bc. on this image there is just a hemicylinder

Answer 2

SA=2πr^2+2πrh

this is formula for SA of a cylinder

Answer 3

Cylinder:
\(SA=2\pi r^2 + 2\pi rh\)
Prism:
\(SA=2B+Ph\)

Plug in your values,
\(SA=2\pi (0.3)^2 + 2\pi (0.3)(0.7)\)
\(SA=2(0.42) + 2.6(0.7)\)

Simplify and add together,
\(SA=1.9\) (half it)
\(SA=2.7\)
\(SA=3.7\)

Now remove the rectangle amount from the surface area,
\(SA=3.7-0.42\)
\(SA=3.28\)

So your surface area would be \(3.28m^2\).

Answer 4

Then you would just multiply \(3.28\) by \(1649\).