Ask a New Question
Menu

Use the image to answer the question.

An illustration shows a 3 D triangular prism with the triangular face as a right triangle. The edges that are not visible are represented by dashed lines. The length and base of the triangular prism measures 15.9 centimeters and 8.9 centimeters. The perpendicular side of the triangular face measures 5 centimeters and the other side measures 16.7 centimeter.

A wooden door stopper needs to be covered with stickers to match the door for a directing contest. If one package of stickers covers a surface area of 75 square centimeters, how many packages of stickers need to be purchased? (Find the closest number to the surface area of the door stopper. Stickers may only be purchase in whole packs

3 answers

First, we need to calculate the surface area of the triangular prism, which consists of 2 triangles and 3 rectangles.

Surface area of the triangles = 2 * base * height / 2 = 2 * 8.9 * 5 / 2 = 44.5 square centimeters
Surface area of the rectangles = (perimeter of the base * height) + (2 * base * length) = (8.9 + 16.7 + 15.9) * 5 + 2 * 8.9 * 15.9 = 41.5 + 283.8 = 325.3 square centimeters

Total surface area = 44.5 + 325.3 = 369.8 square centimeters

Therefore, the closest number to the surface area is 370 square centimeters.

Since one package of stickers covers 75 square centimeters, we need to purchase 5 packages of stickers to cover the door stopper.
heres the answer chioces:
You will need 414.14 cm2 packages of stickers.
You will need 414.14 cm squared packages of stickers.

You will need 5.5 packages of stickers.
You will need 5.5 packages of stickers.

You will need 6 packages of stickers.
You will need 6 packages of stickers.

You will need 7 packages of stickers
The correct answer is:

You will need 6 packages of stickers.