Geometric Shapes
Altitiude
An altitude (for a triangle) is a line through the vertex that is perpendicular to the opposite side.
A perpendicular line is a line that intersects another line in such a way to form right angles.
An altitude (for a quadrilateral with a pair of parallel sides) is a line perpendicular to a base to the opposite side.
Diagonals
A diagonal is a line that runs from one vertex to another.
Perpendicular Bisector
A perpendicular bisector is a line that is perpendicular and bisects another line.
A bisector is a point or line that intersects another line such that the length on either side is equal.
Central Angle
The central angle is the angle created by 2 segments that intersect at the center of the circle and begin at a point on the circle.
Radii
The radius (plural radii) is a line segment that goes from the center of the circle to any point on the circle.
Chord
A chord is a line segment that runs from one point on a circle to another.
Diameter
A diameter is a chord that runs through the center of the circle.