# Geometry Formulas and Definitions

## 27 terms

Square one side.

### Area of a Rectangle

Multiply the base by the height.

### Area of a Parallelogram

Multiply the base by the height.

### Area of a Trapezoid

Add the two bases, divide by two, then multiply the height.

### Area of a Circle

Square the radius and multiply by pi.

### Area of a Triangle

Multiply the base by the height and then divide by two.

### Area of an Equilateral Triangle

Multiply one fourth by the square root of three, then multiply that by one side squared.

Square any side.

### Volume of a Rectangular Prism

Multiply the length by the width by the height.

### Volume of a Cylinder

Multiply the base by the height.

### Volume of a Pyramid

Multiply the base by the height, then divide by three.

### Volume of a Cone

Multiply the base by the height, then divide by three.

### Volume of a Sphere

Cube the radius, multiply by pi, and then multiply by four thirds.

### Arc

A curved line that is part of the circumference.

### Chord

A line segment within a circle which touches two points on the circle.

### Diameter

The longest distance from one point on a circle to the other

### Origin

The center of a circle

### Pi

A number approximately 3.14

The distance from the center of the circle to any point on it

### Sector

A section of the interior of a circle that can have its own area found.

### Tangent

A line perpendicular to the radius which only touches one point of the circle.

### Perimeter of a Rectangle

Multiply both nonparallel sides by two and then add them.

### Perimeter of a Circle

Multiply the radius by two, then multiply it by pi.

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