Question

An aluminum can is a right cylinder. Find the amount of paper needed for the can's label and the total

Answer 1

Answer:

Label: About 527.9 square centimeters

Aluminum: About 835.7 square centimeters

Step-by-step explanation:

Amount of paper needed for the label:

You can imagine taking off the label and unrolling it, forming a rectangle. The height of this rectangle will be the height of the cylinder, while the length of the rectangle will be the circumference of the cylinder. Therefore, the area of that rectangle will be $2\pi r h= 2 \cdot \pi \cdot 7 \cdot 12\approx 527.9$.

Amount of aluminum needed for the can:

This time, you need to add in the top and bottom of the can as well, which each have area $\pi r^2$. Together, they have area $2\pi r^2=2\cdot \pi \cdot 7^2\approx 307.9$. Adding this to the area of the sides, you get a total of about 835.7 square centimeters.

Hope this helps!