# Angle Worksheets

Angle Worksheets
• Page 1
1.
Name $\angle$A, if $\angle$A = 19°.
 a. obtuse angle b. straight angle c. right angle d. acute angle

#### Solution:

If the measure of an angle is less than 90°, it is an acute angle.

Since mA = 19°(< 90°), A is an acute angle.

2.
What is the measure of $\angle$AOB?

#### Solution:

The measure of AOB is greater than 90° but less than 180°.

So, AOB is an obtuse angle.

Among the choices, 120° is the only obtuse angle.

So, measure of AOB is about 120°.

3.
Which of the angles is obtuse?

 a. ÃLOB b. ÃAON c. ÃAOL d. None of the above

#### Solution:

AON is greater than AOL and less than AOB.

AON is greater than 90o and less than 180o.

Obtuse angle is an angle that is greater than 90o and less than 180o.

So, AON is an obtuse angle.

4.
PR is a line segment in the figure shown. Find the value of $y$.

 a. 75o b. 60o c. 15o d. 40o

#### Solution:

PQR = PQA + AQB + BQR

180o = (y + 35o) + 45o + (y + 20o)
[Equation]

180o = 2y + 100o
[Simplify]

180o - 100o = 2y + 100o Ã¢â‚¬â€œ 100o
[Subtract 100o from each side.]

80o = 2y
[Simplify]

80o/2 = 2y / 2
[Divide each side by 2.]

40o = y
[Simplify]

So, the value of y = 40o.

5.
PQRS is a parallelogram. Find the measure of $\angle$2.

 a. 50o b. 55o c. 60o d. 75o

#### Solution:

From the figure, 1 and APB are vertical angles.

1 = 60o
[Vertical angles are congruent.]

PQRS is a parallelogram. In a parallelogram, the opposite angles are equal.

2 and 1 are opposite angles in the parallelogram. 1 = 2

2 = 60o
[Since 1 = 60o]

The measure of 2 = 60o

6.
What is the measure of the exterior angle of triangle ABC?

 a. 145o b. 155o c. 135o d. 125o

#### Solution:

In ΔABC, mABC = 55o and mBCA = 35o

Since side BC is extended to the point D, exterior angle of the triangle is ACD.

In the figure, Interior angle at C + Exterior angle at C = 180o.

mBCA + mACD = 180o
[Substitute the angles.]

35o + mACD = 180o
[Substitute the value of BCA.]

mACD = 145o
[Simplify.]

Measure of the exterior angle of the triangle is 145o.

7.
An angle measuring less than 90° is called _____.
 a. an obtuse angle b. a right angle c. an acute angle d. a straight angle

#### Solution:

An angle measuring less than 90° is called an acute angle.

8.
Identify the angle that measures more than 90°.

 a. angle 1 b. angle 3 c. angle 2 d. angle 4

#### Solution:

In the figure, angle 3, angle 4, and angle 5 are 90°. Angle 1 is less than 90°.

Angle 2 and angle 6 are more than 90°.

So, among the choices angle 2 is more than 90°.

9.
In the figure shown, CD is intersecting AB at O. What is the angle $b$, if $\angle$BOC = 120°?

 a. 90° b. 30° c. 180° d. 60°

#### Solution:

From the figure, BOC + BOD = 180°.

Therefore, 120° + b = 180°.

b = 180° - 120°.

b = 60°
[Simplify.]

10.
In the figure shown, CD is intersecting AB at O. What is the angle $n$ if $\angle$AOC = 58°?

 a. 130° b. 122° c. 128° d. 58°

#### Solution:

From the figure, AOC + BOC = 180°.

58° + n = 180°.

n = 180° - 58° = 122°.

Therefore, the angle 'n' is 122°.