16 terms

complementary angles

_________ are a pair of angles whose measures add to 90∘.

concave polygon

A _________ is a polygon with at least one interior angle whose measure is greater than 180∘.

convex polygon

A _________ is a polygon with all interior angles measuring less than 180∘

exterior angle

An angle at a vertex of a polygon where the sides of the angle are one side of the polygon and the extension of the other side meeting at the vertex.

interior angle

The angle inside a polygon formed by two adjacent sides of the polygon.

irregular polygon

A polygon that has at least two sides with different lengths or two angles with different measures.

polygon

A shape formed by three or more line segments, called sides.

quadrants

The four sections into which the coordinate plane is divided by the x- and y-axes.

regular polygon

A polygon that has all of its sides equal and all of its angles equal.

rotation

A transformation that turns a figure counterclockwise about a point.

supplementary angles

_________ are two angles that form a straight line. The sum of the angles is 180∘.

tiling (also called a tessellation)

The covering of a plane surface with geometric shapes without gaps or overlaps.

vertical angles

_________ are a pair of congruent nonadjacent angles formed by the intersection of two lines.

reflectional symmetry

A shape with _________ has halves that are mirror images of each other.

rotational symmetry

A shape with _________ can be turned about a center point through some angle between 0 and 360 degrees and it will look the same.

transversal

A line that intersects two other lines.