# Cylinder problem:restriction on the height if the radious

1. Sep 20, 2006

### Aoiro

A cylindrical frame consisting of three circles and four vertical supports is built from 6m of wire, as shown. The frame is then covered with paper to form a closed cylinder.
1. Determine an expression for the radius r in terms of the height h.
2. determine the restriction on the height if the radious of the cylendar must be atleast 10.
I got the first one;
1.r=3-2h/3pi
But I did not get the second one
2.
10 > 3- 2h/3pi

3pi(10)> 3- 2h

30pi-3 > -2h

(30pi - 3)/-2 < h

Can someone help me? Thanks

2. Sep 20, 2006

### Integral

Staff Emeritus
A good question would be 10 what? m? Miles? pounds?

Recall that the lenght of the wire is given in meters, so if you try to make a 10m diameter circle you will have troubles.

3. Sep 20, 2006

### Aoiro

^ sorry, 10cm

4. Sep 20, 2006

### Tomsk

You need to use 10cm=0.1m, as you used 6m initially. Also, I think your < is the wrong way round.

5. Sep 20, 2006

^ thank you