Measuring Angles Using a Protractor

This is what kind of angle?

• obtuse
• right
• straight
• acute

Tags

CCSS.4.G.A.1

Why is this not a 85° angle?

• 85° is an acute angle. The picture shows a right angle as it is 90°.

• 85° is an obtuse angle. The picture shows an acute angle as it is less than 90°.

• 85° is an obtuse angle.The picture shows an acute angle as it is less than 90°.

• 85° is an acute angle. This picture shows an obtuse angle as it is more than 90°.

Tags

CCSS.4.G.A.1

CCSS.4.G.A.2

Is this the correct way of using a protractor to measure an angle

• Yes, because the vertex of the angle is aligned with the center point of the protractor.

• No, because the baseline of the protractor is not aligned properly with the bottom ray of the angle.

This is the wrong way of using a protractor because __________.

• the bottom line of the angle is not aligned to the baseline of the protractor.

• the vertex of the angle is not aligned to the center point of the protractor.

Do you agree that ∠a = 90°.

• Yes. The top line of the angle is aligned to 90°.

• No. The measurement is not accurate because the bottom line of the angle is not aligned to the baseline of the protractor.

Tags

CCSS.4.G.A.1

CCSS.4.G.A.2

CCSS.4.MD.C.5

CCSS.4.MD.C.6

_{What is the measure of the following angle?}  

• 21 degrees.
• 34 degrees.
• 70 degrees.
• 172 degrees. 

Tags

CCSS.4.MD.C.5

CCSS.4.MD.C.6

CCSS.4.MD.C.7

_{What is the measure of the angle?}

• 110 degrees. 
• 140 degrees.
• 150 degrees.
• 170 degrees. 

Tags

CCSS.4.MD.C.5

CCSS.4.MD.C.6

CCSS.4.MD.C.7

The amount of the angle above is . . . .

• 60^o

• 80^o

• 120^o

• 140^o

Find the angle above

• 130^o

• 120^o

• 90^o

• 50^o

This is what kind of angle?

• right
• acute
• obtuse
• straight

Tags

CCSS.4.G.A.1

CCSS.4.G.A.2

CCSS.4.MD.C.5