28 terms

adjacent angles

Two angles that have the same vertex, share a common side, and do not overlap.

alternate exterior angles

Nonadjacent exterior angles found on opposite sides of a transversal.

alternate interior angles

Nonadjacent interior angles found on opposite sides of a transversal.

center of rotation

A fixed point around which shapes move in a circular motion to a new position.

complementary angles

Two angles whose sum is 90 degrees.

congruent

Line segments that have the same length, angles that have the same measure, or figures that have the same size and shape.

corresponding angles

Angles that have the same position on two different parallel lines cut by a transversal.

diagonal

A line segment that connects two nonconsecutive vertices.

dilation

A transformation that alters the size of a figure but not its shape.

exterior angle

An angle formed by one side of a triangle and the extension of the adjacent side.

image

Every corresponding point on a figure after its transformation.

interior angle

An angle inside a polygon.

line segment

Part of a line containing two end points and all the points between them.

parallel lines

Two lines on the same plane that do not intersect.

perpendicular lines

Lines that intersect to form a right angle.

polygon

A simple closed figure formed by three or more straight line segments.

reflection

A transformation where a figure is flipped over a line.

regular polygon

A polygon that has all sides congruent and all angles congruent.

rotation

A transformation where a figure is turned around a fixed point.

rotational symmetry

A figure has rotational symmetry if it can be rotated less then 360 degrees about its center and still look like the original.

supplementary angles

Two angles whose sum is 180 degrees.

tessellation

A pattern formed by repeating figures that fit together without any gaps or overlaps.

transformation

A movement of a geometric figure.

translation

A transformation where a figure is slid from one position to another without being turned.

transversal

A line that intersects two parallel lines to form 8 angles.

triangle

A figure having three sides.

vertex

A vertex of a polygon is a point where two sides of a polygon intersect.

vertical angles

Two pairs of opposite angles formed by to intersecting lines. The angles formed are congruent.