Category 1: Angle Types
Classify a 45° angle.
What is Acute?
One angle is 70°.
Find the other angle on the straight line.
What is 180°−70°=110°?
One angle is 90° and another is 180° around a point.
Find the missing angle.
90°+180°=270°
360°−270°=90°
What is 90°?
Is a 75° angle acute, right, or obtuse?
What is Acute?
One angle on a straight line is 65°. Find the missing angle.
What is 115°?
Classify a 120° angle.
What is Obtuse?
Angles are 50°, 60°, and one missing on a straight line.
50°+60°=110°
180°−110°=70°
What is 70°?
Angles are 100°, 80°, and one missing around a point.
100°+80°=180°
360°−180°=180°
What is 180°?
An angle on a straight line looks slightly smaller than a right angle. Estimate its size.
What is ~80°?
Angles around a point: 200° and 100°. Find the missing angle.
What is 60°?
360 − 200 − 100
What is the name of an angle that measures exactly 180°?
What is/are Straight Lines?
A straight line is divided into three angles. Two of the angles measure 40° and 75°. What is the measure of the third angle?
40°+75°=115°
180°−115°=65°
What is 65°?
Angles are 120°, 60°, 40°, and one missing around a point.
120°+60°+40°=220°
360°−220°=140°
What is 140°?
A very large angle looks almost like a straight line. Estimate it.
What is ~170°?
Angles on a straight line: 50°, 40°, and one missing.
What is 90°?