Types
is exactly 90 degrees.
right angle
Look at figure 1.
Right angle, 90 degrees.
Look at figure 6.
46 degrees.
a full turn is how many degrees?
360 degrees
What is the definition of an angle?
When two rays meet at a vertex.
is between 90 and 180 degrees.
obtuse angle
Look at figure 2.
72 degrees.
Look at figure 7.
128 degrees.
180 degrees is ______ - turn.
1/2
What is a vertex?
One point shared by two rays.
is smaller than 90 degrees.
acute angle
Look at figure 3.
<ABC or <CBA, acute angle, 50 degrees.
Look at figure 8.
68 degrees.
3/4 -turn is how many degrees? 1/4- turn is how many degrees?
270 degrees, 90 degrees.
What tool do we use to measure angles?
a protractor.
is exactly 180 degrees.
straight angle
Look at figure 4.
acute angle, 60 degrees. Obtuse angle, 150 degrees.
Look at figure 9.
24 degrees.
How many 45 degree turns would it take to make 1 full turn?
8 turns.
What is the name of two angles that make up a straight angle?
supplementary angles.
is greater than 180 degrees.
reflex angle
Look at figure 5.
<BOA or <ABO, acute, 60 degrees.
Look at figure 10.
Rachel was facing the mall. She turned 1/4 turn to the left. She then turned 3/4 turn to the right. What fraction of a turn would she need to face the mall again?
1/2 turn, 180 degrees.
What is the name of two angles that form a right angle?
complementary angles.