Polygons
A polygon with six sides and six angles
hexagon
An angle that has a measure less than a right angle (less than 90°)
Acute Angle
A quadrilateral whose opposite sides are parallel and congruent
Parallelogram
A polygon with three sides
Right Triangle
A closed plane figure with all points on the figure the same distance from the center
Circle
A polygon with eight sides
Octagon
In angle whose measure is greater than 90° and less than 180°
Obtuse Angle
A polygon with four sides
Quadrilateral
A triangle with one right angle
Right Triangle
The distance around a circle is called
Circumference
A polygon with five sides
Pentagon
180 degree angle
Line
A parallelogram with four right angles
Rectangle
A triangle in which all three angles are acute
Acute Triangle
A line segment with its endpoints on a circle
Chord
A polygon with 9 sides
Nongon
An angle formed by perpendicular lines, line segments, or rays and with a measure of 90°
Right Angle
A rectangle with 4 equal sides
Square
A triangle that has one obtuse angle
Obtuse Triangle
A line segment that passes through the center of
a circle and has its endpoints on the circle
Diameter
A polygon with 7 sides
Heptagon
A figure formed by two rays that have a common endpoint
Angle
A quadrilateral with one pair of parallel sides
Trapezoid
A triangle with no congruent sides
Scalene Triangle
A line segment with one endpoint at the center of a circle and the other endpoint on the circle
Radius