Acute angle
An angle that measures greater than zero and less than 90
Adjacent angles
Two angles in the same plane with a common vertex and a common side, but no common interior points
Angle
I figure formed by two rays with a common endpoint
Angle bisector
A ray that divides an angle into two congruent angles
Area
The number of non-overlapping unit squares of a given size that will exactly cover the interior of a plane figure
Bisect
To divide into Two congruent parts
Circumference
The distance around a circle
Collinear
Points that lie on the same line
Complementary angles
Two angles whose measures have a sum of 90°
Congruent angles
Angles that have the same measure