Practice with the help of **Spectrum Math Grade 5 Answer Key Chapter 9 Lesson 9.4 Classifying Angles **regularly and improve your accuracy in solving questions.

## Spectrum Math Grade 5 Chapter 9 Lesson 9.4 Classifying Angles Answers Key

A protractor is used to measure an angle. The angle is measured in degrees.

A right angle measures exactly 90°.

An acute angle measures less than 90°.

An obtuse angle measures greater than 90° but less than 180°.

**Identify each angle as right, acute, or obtuse.**

Question 1.

a.

Type of Angle ______________

Answer: Acute angle

The type of angle in the above figure is acute angle.

An acute angle measures less than 90°.

b.

Type of Angle ______________

Answer: Acute angle

The type of angle in the above figure is acute angle.

An acute angle measures less than 90°.

Question 2.

a.

Type of Angle ______________

Answer: Obtuse angle

The type of angle in the above figure is obtuse angle.

An obtuse angle measures greater than 90° but less than 180°.

b.

Type of Angle ______________

Answer: Acute angle

The type of angle in the above figure is acute angle.

An acute angle measures less than 90°.

Question 3.

a.

Type of Angle ______________

Answer: Right angle

The type of angle in the above figure is right angle.

A right angle measures exactly 90°.

b.

Type of Angle ______________

Answer: Obtuse angle

The type of angle in the above figure is obtuse angle.

An obtuse angle measures greater than 90° but less than 180°.

**Use a protractor to measure each angle. Then, label each angle right, acute, or obtuse.**

Question 1.

a.

∠ ____________ = ____________

Answer: ∠ ABC = 60 degrees

The type of angle in the above figure is acute angle.

An acute angle measures less than 90°.

b.

∠ ____________ = ____________

Answer: ∠ GHI = 90 degrees

The type of angle in the above figure is right angle.

A right angle measures exactly 90°.

Question 2.

a.

∠ ____________ = ____________

Answer: ∠ PQR = 110 degrees

The type of angle in the above figure is obtuse angle.

An obtuse angle measures greater than 90° but less than 180°.

b.

∠ ____________ = ____________

Answer: ∠ XYZ = 170 degrees

The type of angle in the above figure is obtuse angle.

An obtuse angle measures greater than 90° but less than 180°.

Question 3.

a.

∠ ____________ = ____________

Answer: ∠ 123 = 90 degrees

The type of angle in the above figure is right angle.

A right angle measures exactly 90°

b.

∠ ____________ = ____________

Answer: ∠ ABC = 30 degrees

The type of angle in the above figure is acute angle.

An acute angle measures less than 90°.

**Find the measure of each angle of the given triangle. Label each angle as right, acute, or obtuse.**

Question 4.

a.

∠ ____________ = ____________

It is _______________.

∠ ____________ = ____________

It is _______________.

∠ ____________ = ____________

It is _______________.

Answer:

∠ ABC = 60 degrees

It is Acute angle.

The type of angle in the above figure is acute angle.

An acute angle measures less than 90°.

∠BCA = 60 degrees

It is Acute angle.

The type of angle in the above figure is acute angle.

An acute angle measures less than 90°.

∠ CAB= 60 degrees

It is Acute angle.

The type of angle in the above figure is acute angle.

An acute angle measures less than 90°.

b.

∠ ____________ = ____________

It is _______________.

∠ ____________ = ____________

It is _______________.

∠ ____________ = ____________

It is _______________.

Answer:

∠ XYZ = 90 degrees

It is Right angle.

The type of angle in the above figure is right angle.

A right angle measures exactly 90°

∠ YZX = 45 degrees

It is Acute angle.

The type of angle in the above figure is acute angle.

An acute angle measures less than 90°.

∠ ZXY = 45 degrees

It is Acute angle.

The type of angle in the above figure is acute angle.

An acute angle measures less than 90°.