## Tuesday, April 15, 2008

### Angelo's B.O.B

This blog is about the steps to find the surface area and the volume for a cube and a rectangular prism. When doing work for a cube or a rectangular prism you need to include the 3D diagram and their net.

This is the 3D version of a cube :

This is the cube's net :

This is an example of a rectangular prism :

This is it's net :

There are several ways to find a surface area for both of the shapes. One way for the cube is this :

It is clear that if you get the areas of each square in the cube you already can solve the surface area of the cube. You can solve the area of each side by multiplying the two different measurements that make the side. For example, if one side is made up by 2 lengths and 2 widths, you multiply the width and length together to get the area. So if you already have all the areas, just add all six sides together and get the Surface Area.

There are two steps used to solve both of the shapes. I used one of them on the cube.

All you have to do is find the base and multiply that answer with the height. To find the "base" of a shape, all you have to do is multiply it's length with the width.

Now moving on to the rectangular prism. The step I used for this shape can also be used on a cube.

This step take more time. If you multiply length and width, you are finding the area for the Top or the Bottom parts of the shape. If you multiply length and height, you are finding the area for the Front or Back. And if you multiply width and height, you obviously get the area for one of the two sides. Since there are six sides. Once you find the area for one side of the shape, times it by two to get the other side. For example, if you find the area for the Top, just multiply it by two so you can get the area for the Bottom also.
Yes, these steps on finding the volume of a rectangular prism can also be used to find the volume of a cube :

This explanation is quite simple. If you multiply the length and width, find the answer and multiply that to the height. Once your done that, you have solved the volume.

Now...you guys should know how to find the Surface Area and the Volume of a Cube and also a Rectangular Prism.