# Unit 12: Measurement of 3D Figures

## 9 terms · relates to chapter 10 lessons 1,2 and 4

### prism

A polyhedron that has two congruent polygon-shaped bases and other faces that are all parallelograms.

### face

A flat surface of a polyhedron.

### edge

The line segment along which two faces of a polyhedron intersect.

### vertex

On an angle or polygon, the point where two sides intersect.

### volume of a triangular prism

The number of cubic units needed to fill a given space. Volume is the area of the base times the height: V = Bh. For a triangular base you must first find the area of the triangle using A=bh/2. This number becomes the B in the volume formula.

### surface area

The sum of the areas of the faces, or surfaces, of a three-dimensional figure.
S = 2lw + 2lh + 2wh

### net

An arrangement of two-dimensional figures that can be folded to form a polyhedron.

### pyramid

a polyhedron with a polygon base and triangular sides that all meet at a common vertex.

### Rectangular Prism

The volume of a rectangular prism is the area of its base times its height. For the area of a rectangular base use A=l*w. This number will then be used as the B in the volume formula: V=Bh