This handy Math in Focus Grade 5 Workbook Answer Key Chapter 13 Practice 2 Measures of Angles of a Triangle provides detailed solutions for the textbook questions.

## Math in Focus Grade 5 Chapter 13 Practice 2 Answer Key Measures of Angles of a Triangle

**Complete.**

Question 1.

m∠A + m∠B + m∠C = ____

Answer:

m∠A + m∠B + m∠C =180°

Explanation:

The property of a triangle is : The sum of all internal angles of a triangle is always equal to 180^{°}^{.}

m∠A + m∠B + m∠C = 180°

Question 2.

80° + 70° + m∠F = ___

m∠F = ___

Answer:

80° + 70° + m∠F = 180°

m∠F = 30°

Explanation:

The property of a triangle is : The sum of all internal angles of a triangle is always equal to 180^{°}^{.}

80° + 70° + m∠F = 180°

m∠F = 180°- 80° + 70° = 30°

**Measure the angles of the triangle. Then fill in the blanks.**

Question 3.

m∠A = ___

m∠B = ___

m∠C = ____

m∠A + m∠B + m∠C = __ + ___ + ___

= ____

The sum of the angle measures in the triangle is ___

Answer:

m∠C = 40°

m∠B = 60°

The sum of angles in a triangle are 180°

40 + 60 = 100

180 – 100 = 80°

m∠A = 80°

m∠A = 80°

m∠B = 40°

m∠C = 60°

m∠A + m∠B + m∠C = 80°+ 40°+ 60° = 180°

**These triangles are not drawn to scale. Find the unknown angle measures.**

Question 4.

Find the measure of ∠B.

Answer:

m∠B = 75°

Explanation:

The property of a triangle is : The sum of all internal angles of a triangle is always equal to 180^{°}^{.}

43° + 62° + m∠B = 180°

m∠B = 180° – 43° + 62° = 75°

Question 5.

Find the measure of ∠D.

Answer:

m∠D = 68°

Explanation:

The property of a triangle is : The sum of all internal angles of a triangle is always equal to 180^{°}^{.}

72° + 50° + m∠D = 180°

m∠D = 180° – 72° + 50° = 68°

Question 6.

Find the measure of ∠H.

Answer:

m∠H = 139°

Explanation:

The property of a triangle is : The sum of all internal angles of a triangle is always equal to 180^{°}^{.}

15° + 26° + m∠H = 180°

m∠H = 180° – 15° + 26° = 139°

Question 7.

Find the measure of ∠QPS.

Answer:

m∠QPS = 38°

Explanation:

The property of a triangle is : The sum of all internal angles of a triangle is always equal to 180^{°}^{.
}In Triangle PQR

60° + 32° + m∠QPR = 180°

m∠QPR = 180° – 60° + 32° = 88°

then as per the diagram

m∠QPS = m∠QPR – m∠RPS = 88° – 50° = 38°