# Naming Angles Worksheet

Naming Angles Worksheet
• Page 1
1.
UC and UT are opposite rays. $\angle$CUT is _________ .

 a. a complete angle b. a supplementary angle c. an obtuse angle d. a straight angle

#### Solution:

UC and UT are opposite rays.

CUT = 180o

Straight angle = 180o.

So, CUT is a straight angle.

2.
Which of the following choices is correct for the statement, 'a straight angle is two times a right angle'?
 a. Always true b. False c. Some times true d. None of the above

#### Solution:

Straight angle measures 180o and a right angle measures 90o.

Two times a right angle = 2 × 90o = 180o, a straight angle.

The statement is always true.

3.
Find the measure of $\angle$ABC.

 a. 115° b. 85° c. 75° d. 65°

#### Solution:

ABC is made up of two rays, BC and BA with the common endpoint B.

ABC is the measure between BC and BA.

On the protractor scale, BC is passing through zero and BA is passing through 65°.

The measure of ABC is 65°.

4.
Find the measure of $\angle$PQR.

 a. 100° b. 70° c. 180° d. 120°

#### Solution:

PQR is made up of two rays, QR and QP with the common endpoint Q.

PQR is the measure between QR and QP.

On the protractor scale, QR is passing through zero and QP is passing through 100°.

The measure of PQR is 100°.

5.
Find the measure of $\angle$STU.

 a. 105° b. 45° c. 135° d. 180°

#### Solution:

STU is made up of two rays, TU and TS with the common endpoint T.

STU is the measure between TU and TS.

On the protractor scale, TU is passing through 180° and TS is passing through 45°.

Difference = 180° - 45° = 135°.
[Subtract.]

The measure of STU is 135°.

6.
Find the measure of $\angle$KLM.

 a. 160° b. 180° c. 30° d. 20°

#### Solution:

KLM is made up of two rays, LM and LK with the common endpoint L.

KLM is the measure between LM and LK.

On the protractor scale, LM is passing through 180° and LK is passing through 160°.

Difference = 180° - 160° = 20°.
[Subtract.]

The measure of KLM is 20°.

7.
What is the measure of $\angle$TQP?

 a. 40° b. 120° c. 30° d. 110°

#### Solution:

TQP is made up of two rays, QT and QP with the common endpoint Q.

TQP is the measure between QT and QP.

On the protractor scale, QT is passing through 30° and QP is passing through 140°.

Difference = 140° - 30° = 110°.
[Subtract.]

The measure of TQP is 110°.

8.
Name the angle.

 a. $\angle$RPQ b. $\angle$QPR c. $\angle$PRQ d. $\angle$RQP

#### Solution:

An angle is made up of two rays with a common endpoint.

In the figure, there are two rays QP and QR with a common endpoint Q.

Q is the vertex and QP, QR are two rays.

So, the angle made by the two rays and the common endpoint is RQP.

9.
If one angle of a linear pair is acute, then what is the other angle?
 a. Acute Angle b. Obtuse Angle c. Right Angle d. None of the above

#### Solution:

If the sum of two angles of two intersecting lines is 180o, then, the angles form a linear pair.

Acute angle is one whose measure is less than 90o and obtuse angle is one whose measure is more than 90o.

Hence, in a linear pair, if one angle is acute (below 90o) then the other angle must be obtuse (above 90o).

10.
A 42 mm lens has a 80° viewing angle. What kind of angle is this?
 a. acute b. obtuse c. reflex d. right

#### Solution:

42 mm lens has 80° viewing angle.

If the angle is below 90°, then the angle is called an acute angle.

80° < 90°. So, the viewing angle is an acute angle.