Go Math Chapter: 11 Angles
right angle
an angle that forms a square corner and has a measure of 90 degrees
obtuse angle
an angle that measures greater than 90 degrees and less than 180 degrees
acute angle
an angle that measures less than 90 degrees and greater than 0 degrees
ray
part of a line that has one end point, and continues without end in one direction
90 degrees
right angle measurement
180 degrees
straight angle
vertex
the point at which two rays on an angle meet or two (or more) line segments meet in a two 2D shape.
360 degrees
the total measure of degrees in a circle
3/4 turn
270 degrees around a circle
5 min on a clock or 1/12 of a circle
30 degrees
whole turn
360 degrees around a circle
1/4 turn
90 degrees around a circle
protractor
A tool used for measuring the size of an angle
counterclockwise
In the opposite direction in which the hands of a clock move
clockwise
In the same direction in which the hands of a clock move
degree
The unit used for measuring angles
1/360 of a circle
1 degree
1/2 turn
180 degrees around a circle