Vocabulary
What is a tool used to measure angles?
A Protractor
How many rays make an angle?
2
Less than 90°?
Acute Angle
Where do you place the center of the protractor?
On the vertex
A straight line measures how many degrees?
180°
What is the point where two rays meet?
The Vertex
What part of the angle is the “corner”?
The Vertex
Exactly 90°?
Right Angle
What must you line up with one ray?
The baseline
A full circle measures how many degrees?
360°
What is the unit used to measure angles?
Degrees
True or False: An angle can have 3 rays
False
Greater than 90° but less than 180°?
Obtuse Angle
What do you read to find the angle?
The number where the second ray crosses
Is a 90° angle acute, right, or obtuse?
Right
What is a ray?
A line that goes on forever in one direction
What do rays always share in an angle?
A common endpoint
Is 120° acute, right, or obtuse?
Obtuse
What happens if the protractor is not lined up correctly?
The measurement will be wrong
Which is larger: 60° or 120°?
120°
What is an angle?
Two rays that share a common endpoint
Name both parts of an angle
2 Rays and the vertex
Is 45° acute, right, or obtuse?
Acute
What is the first step when measuring an angle?
Place the center on the vertex
List all steps to measure an angle using a protractor
Place center on vertex
Line up baseline
Read where the ray crosses