Question

The rectangular label will completely cover the lateral surface of the can using as little paper as possible. If the can has a height of 12 cm and a diameter of 5 cm, then what are the width and length (to the nearest centimeter) of the label? I absolutely am stuck on this q :/

Answer 1

It's asking you for the length and width of the side of a cylinder.

Answer 2

so you unwrap the cylinder... the width is the circumference of the top, after you unwrap it.

Answer 3

the height of the label is 12 and the width is 15?

Answer 4

width = circumference = pi * diameter = about 3.14 * 5... then you round to nearest cm.

Answer 5

did i get it right then?

Answer 6

If you take 3.4 as "pi", then pi * 5 = 15.7

Answer 7

I would round that up...

Answer 8

oh then 16

Answer 9

Does "unwrapping" the cylinder makes sense to you? That's how I think of the area of the side... not sure it makes sense for everyone though.

Answer 10

idk, i have probs with math :/

Answer 11

but thx :D

Answer 12

:D

Answer 13

nah, you're fine :) If you can grab a soda can or whatever and wrap a piece of paper around it, you can see that the side of a cylinder "unwraps" to look like a rectangle.

Or peel the label off some can... it's a rectangle shape.