Geometry Chapter 1

### perpendicular bisector

a segment, ray, line, or plane that is perpendicular to a segment at its midpoint

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### Midpoint Formula

M = [ ( x₂ + x₁) / 2, (y₂ + y₁) / 2 ]

To get your x-coordinate: Add the x's and divide by 2

To get your y-coordinate: Add the y's and divide by 2

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### Distance formula

d = √[( x₂ - x₁)² + (y₂ - y₁)²]

It does not matter which point is labeled 1 and which is labeled 2

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### Circumference of a Circle

C=2πr or C=πd

where r = radius and d = diameter and π = pi (approx. 3.14)

### Flickr Creative Commons Images

Some images used in this set are licensed under the Creative Commons through Flickr.com. Click to see the original works with their full license.

- “acute angle” image
- “angle” image
- “area” image
- “circumference” image
- “congruent angles” image
- “line” image
- “obtuse angle” image
- “parallel lines” image
- “parallel planes” image
- “perpendicular bisector” image
- “perpendicular lines” image
- “right angle” image
- “skew lines” image
- “straight angle” image
- “vertical angles” image