Variable
A letter that is used to represent one or more numbers.
Complementary Angles
Two angles whose measures have a sum of 90°.
Adjacent Angles
Two angles in a plane that share a common side and a vertex and do not overlap.
Radius
The distance between the center and any point on the circle.
Pi (∏)
The ratio of the corcumference of a circle to its diameter.
Supplementary Angles
Two angles whose measures have a sum of 180°.
Diameter
The distance across the circle through its center.
Quadrilateral
A geometric figure made up of four line segments, called sides, that intersect only at their endpoints; a polygon with four sides.
Area
The numbers of square units needed to cover a figure.
Volume
The amount of space the solid occupies.
Circumference
The distance around a circle.
Vertical Angles
A pair of opposite angles formed when two lines meet at a point.
Acute Triangle
A triangle whose measure is less than 90°.
Right Triangle
A trianglw whose measure is exactly 90°.
Obtuse Triangle
A triangle whose measure is between 90° and 180°.
Equlaterial Triangle
A triangle with three congruent sides.
Isosceles Triangle
A triangle with at least two congruent sides.
Scalene Triangle
A triangle with no congruent sides.