## What are the prisms

At the base of a prism can be any polygon – a triangle, a quadrilateral, a Pentagon, etc. Both bases are exactly the same, and accordingly, the ribs, which angles of parallel faces connected to each other, always parallel. At the base proper of the prism lies in a regular polygon, that is, one in which all sides are equal. Straight prism edges between the side faces perpendicular to the base. At the base of a right prism can be a polygon with any number of corners. Prism whose base is a parallelogram is called a parallelepiped. A rectangle is a special case of a parallelogram. If the base is exactly the shape, and the side face located to the base at a right angle, is called rectangular parallelepiped. The second name of this geometric body is a rectangular prism.

## How it looks

Rectangular prisms in the environment of modern man quite a lot. This, for example, a conventional cardboard box from under footwear, computer components, etc. look Around. Even in the room you will see many rectangular prisms. This computer case, bookshelf, refrigerator, wardrobe, and many other items. Form is extremely popular mainly because it allows you to use the space as efficiently as possible, regardless of, you make out interior or pack in cardboard boxes prior to moving in.

## Properties of a rectangular prism

A rectangular prism has a number of specific properties. Any pair of faces can serve its reason, since all the adjacent faces are located to each other under the same angle, and this angle is 90°. The volume and surface area of rectangular prism to calculate easier than any other. Take any object having the shape of a rectangular prism. Measure its length, width and height. To find the volume of a rectangular parallelepiped, it is sufficient to multiply these measurements. That is, the formula is: V=a*b*h, where V is volume, a and b – side of the base, h is the height, which in this geometry coincides with the side edge. The footprint is calculated by the formula S1=a*b. To find the lateral surface area, we first need to calculate the perimeter of the base by the formula P=2(a+b) and then multiply it by the height. It turns out the formula S2=P*h=2(a+b)*h. To calculate the full surface of the rectangular prism fold twice the square base and the lateral surface area. Get the formula S=2S1+S2=2*a*b+2*(a+b)*h=2[a*b+h*(a+b)]