Classifying Angles
An angle that measures 83 degrees is...
an acute angle
Angles that measure less than 90 degree
are acute angles
What is the definition of an angle?
The space between two rays or lines that meet at a point called the vertex
Where do you place an protractors midpoint when measuring an angle?
Directly on the vertex of the angle
An angle that measures 123 degrees is...
an obtuse angle
An angle that measures 180 degrees
is a straight angle
What do you need to measure angles?
A protractor
Do you need to align one arm of the angle with the O degree line on the protractor?
yes
An angle that measures 90 degrees is..
A right angle
An angle that measures more than 180 degrees but less than 360 degrees is a...
reflex angle.
What are the components of an angle?
Hint: there are three
Vertex, Arms and Interior
How do I read what the the angle is
Read the measure in degrees where the arm interacts the scale.
An angle that measures 180 degrees is...
a straight angle
An angle that opens "wider" than a right angle and measures more than 90 degrees
is an obtuse angle
What measurement is used to measure angles?
Degrees
How do you determine which scale to use, the inner or outer?
Look at the size of the angle, if it is less than 90 degrees use the inner if it is bigger use the outer
An angle that measures 89.3 is...
an acute angle
An angle that measures 360 degrees is a
revolution angle.
How many angles have we looked at this lesson?
6
What are some of the common errors?
- Misaligning the centre point
- Reading from the wrong scale
- Not placing the baseline along one arm.