It measures exactly 90 degrees.
Right angle
Parallel lines
Obtuse angle
Acute angle
It’s less than 90 degrees.
Obtuse angle
Acute angle
Parallel lines
Right angle
It’s more than 90 degrees but less than 180 degrees.
Right angle
Acute angle
Parallel lines
Obtuse angle
They never meet and stay the same distance apart.
Right angle
Parallel lines
Obtuse angle
Acute angle
They meet at right angles, forming 90-degree angles.
Perpendicular lines
Parallel lines
Acute angle
Obtuse angle
They add up to 180 degrees, like steps on a staircase.
Acute angle
Obtuse angle
Straight line
Parallel lines
What do all angles in a circle equal to?
It’s less than 90 degrees
It’s more than 90 degrees but less than 180 degrees
They add up to 360 degrees
They meet at right angles, forming 90-degree angles.
Identify the angle
Right angle (equal to a right angle)
Identify the angle
Acute angle (less than a right angle)
Identify the angle
Obtuse angle (greater than a right angle)
Identify the angle
Acute angle (less than a right angle)
Find the measure of the unknown angle
72
61
111
71
Find the measure of the unknown angle
64
74
114
54
Find the measure of the unknown angle
68
67
66
65
Find the measure of the unknown angle
109
106
108
107
Find the measure of the unknown angle
51 + 90 = 141 ; 180 - 141 = 39
