The distance around a circle
Circumference
A geometric object produced using only a compass and a straightedge
Construction
Two angles that are supplementary and adjacent
Linear pair
Segments that intersect to form right angles
Perpendicular
a flat surface that has no thickness
Plane
a segment that intersects another segment at its midpoint
segment bisector
A parallelogram with four congruent sides and four right angles
square
a point shared by two segments or rays
vertex
Two angles that sum to 180 degrees
supplementary angles
a triangle with three congruent sides
equilateral triangle
a portion of a line having one end point
ray
a parallelogram with four right angles
rectangle
an angle whose measure is exactly 90 degrees
right angle
a portion of a line having two end points
segment
two angles formed by intersecting lines which only share a common vertex
vertical angles
objects that lie on the same line
coplanar
a parallelogram with four congruent sides
Rhombus
non-coplanar lines that never intersect
Skew lines