Complementary Angles

Two angles whose sum is 90 degrees.

Supplementary Angles

Two angles whose sum is 180 degrees.

Vertical Angles

A pair of opposite congruent angles formed by intersecting lines.

Interior Angles

Angles inside a polygon.

Exterior Angles

Angles on the outside of a polygon by extending the sides of the polygon.

Sum of Interior Angles Formula

(n-2)⋅180°

360°

Sum of Exterior Angles

Transversal

A line that intersects two or more lines.

Corresponding Angles

Two congruent angles in matching positions on two parallel lines cut by a transversal.

Alternate Interior Angles

Two congruent angles that lie within two parallel lines and on opposite sides of the transversal.

Alternate Exterior Angles

Two congruent angles that lie outside two parallel lines and on opposite sides of the transversal.

Same-side Interior Angles

Two supplementary angles that lie within two parallel lines and on the same side of the transversal.

Same-side Exterior Angles

Two supplementary angles that lie outside two parallel lines and on the same side of the transversal.

Measure of an interior angle of a regular polygon

(n-2)⋅180°÷n

Measure of an exterior angle of a regular polygon

360°÷n

Transformation

A change made to the location or the size of a figure.

Image

The new figure formed from a transformation.

A'

Prime notation to identify the image point.

Translation

A transformation in which the figure slides.

Coordinate Notation

(x,y) -> (x + 7, y - 4)

Tessellation

Covering a plane (piece of paper) with repeating pattern of one or more shapes with no gaps or overlaps.

180°

A tessellation can be created with a polygon whose adjacent angles add to __________.

Reflection

A transformation in which the figure is flipped over a line.

Line of Symmetry

A line that divides the figure into two reflecting parts.

Rotation

A transformation in which a figure is turned about a fixed point.

Rotational Symmetry

A figure that when rotated, looks the same as the original.

Order of Rotational Symmetry

How many matches a figure has of itself as it is rotated once 360°.

Dilation

A transformation that shrinks or enlargens with respect to a fixed point.

Scale Factor

The ratio of the image to the original figure.

Dilation Notation

(x,y) -> (kx, ky), Given k, the scale factor such that k>0

Shrink

0<Scale Factor<1

Enlargen

Scale Factor>1

Reflection of x-axis

(x, -y)

Reflection of y-axis

(-x,y)

Reflection of y=x

(y,x)

Reflection of y=-x

(-y,-x)

90° Clockwise rotation about the origin

(y, -x)

90° Counterclockwise rotation about the origin

(-y,x)

180° Rotation about the orgin

(-x,-y)