Geometry Final Prep

Point

Represented by a dot, a capital letter and placed on the coordinate plane (x,y). Has zero dimension.

Line

A one-dimensional figure with length but no width. It is determined by two points in a two dimensional plane, and is named based on two points or a lower case letter (e.g. line m)

Line segment

A line segment is a line with a starting point and an endpoint. It is named after these points (e.g. a segment with three points would be named after the first and second). Also one dimensional.

Ray

Two points beyond one of which the line continues infinitely. One dimensional, named after the two points.

Plane

A plane is a two dimensional space that is named after three non-collinear points (points on different lines). It can also be named after a provided upper case letter (e.g. plane ABC can be plane m).

Two lines intersect at a ....

Point

Two planes intersect at a...

Line

Is congruency represented by the sign: =

No

Is congruency represented by the sign: ≅

Yes

Reflections: Over the y-axis is

(x,-y)

Reflections: Over the x-axis is

(-x,y)

Reflections: Over the line y=x

(y,x)

Reflections: Over the line y=-x

(-y,-x)

Reflections: Through the origin

(-x,-y)

When you rotate by 90 degrees clockwise, it is:

(y,-x)

When you rotate by 90 degrees counterclockwise, it is:

(-y,x)

When you rotate by 270 degrees counterclockwise, it is:

(y,-x)

When you rotate by 270 degrees clockwise, it is:

(-y,x)

Midpoint

Makes a segment into two, proves those halves congruent

Bisect

Divides a segment or angle into 2 equal parts

Segment Addition

Proves that combining two parts of a segment equals to the overall one

Angle Addition

Proves that combining two parts of a angle equals to the overall one

POE (Properties of Equality)

Addition, Subtraction, Multiplication, Division, and Substiution

Linear Pair Postulate

Angles combined equal 180

Vertical angles postulate

Angles opposite each other are equal (sometimes sum to 180)