Shapes and Designs

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.
A shape formed by three or more line segments, called sides.
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.
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.
A line that intersects two other lines.