# Math Help - Width and Height of Solid

1. ## Width and Height of Solid

The length of a rectangular solid is 7. The width of the solid is 2 more than the height. The volume of the solid is 105. Find the width and the height of the solid.

2. Hello,
Originally Posted by magentarita
The length of a rectangular solid is 7. The width of the solid is 2 more than the height. The volume of the solid is 105. Find the width and the height of the solid.
Let l, w, h be respectively the length, the width and the height of the solid.

We know that the volume of such a shape is defined as being : V=h*l*w
We know that w=2h ("the width is 2 more than the height)

So $105=7*2h*h=14h^2$

Hence $h^2=\frac{105}{14}=\frac{15}{2}$

this is the height. Multiply by 2 to get the width

3. ## ok....

Originally Posted by Moo
Hello,

Let l, w, h be respectively the length, the width and the height of the solid.

We know that the volume of such a shape is defined as being : V=h*l*w
We know that w=2h ("the width is 2 more than the height)

So $105=7*2h*h=14h^2$

Hence $h^2=\frac{105}{14}=\frac{15}{2}$

this is the height. Multiply by 2 to get the width
A very nice reply.