Measuring Angles with a Protractor - Worksheet | Maths Year 5 - Free Printable

Let's solve the worksheet step by step.

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1. Measure the angles below.

We are given six diagrams (a to f), each showing an angle with a protractor overlaid. We need to read the angle measurement from the protractor.

#### Key Tips for Using a Protractor:
- Place the center of the protractor at the vertex of the angle.
- Align one arm of the angle with the 0° line on the protractor.
- Read the angle where the other arm crosses the scale.
- Use the correct scale (inner or outer) depending on which side the angle opens.

Now, let’s go through each:

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#### a)
- The angle opens to the right, and the base is aligned with the 0° mark on the bottom (outer) scale.
- The other arm points to 50° on the outer scale.
- ✔ Answer: 50°

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#### b)
- The angle opens upward, starting from the left side.
- One arm is along the 0° line on the left, so we use the outer scale.
- The other arm points to 90°.
- ✔ Answer: 90°

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#### c)
- Angle opens to the right, starting from the left (0°).
- The other arm is pointing to 120° on the outer scale.
- ✔ Answer: 120°

Wait — but the question says "Measuring Acute Angles", and 120° is obtuse. Let’s double-check.

But looking closely: The red lines show a smaller angle between the two arms. However, in this diagram, the angle appears to be greater than 90°, so it's not acute. But since the worksheet includes it, perhaps it's just part of practice.

Still, based on the protractor:
- The outer scale shows the ray pointing at 120°.
- So the angle is 120°.

But wait — the acute angle would be the smaller one. However, the angle shown is clearly greater than 90°, so it's obtuse.

But let’s assume the worksheet wants us to measure what’s shown.

✔ Answer: 120°

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#### d)
- The angle opens to the right, from the left arm at 0°.
- The other arm points to 30° on the outer scale.
- ✔ Answer: 30°

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#### e)
- The angle opens upward from the left.
- The bottom arm is at 0°, and the top arm points to 60° on the outer scale.
- ✔ Answer: 60°

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#### f)
- The angle opens to the right, from the left arm at 0°.
- The other arm points to 70° on the outer scale.
- ✔ Answer: 70°

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✔ Summary of Part 1:

| Letter | Angle |
|--------|-------|
| a) | 50° |
| b) | 90° |
| c) | 120° |
| d) | 30° |
| e) | 60° |
| f) | 70° |

> Note: Only angles less than 90° are acute. So a), d), e), f) are acute; b) is right; c) is obtuse.

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2. Circle the measurement that is most likely for the angles below.

We are given three angles and must choose the best estimate from options.

#### a)
- The angle looks small, like less than 90°.
- Options: 130°, 30°, 90°
- It’s clearly less than 90°, and quite narrow → probably around 30°
- ✔ Answer: 30°

#### b)
- This angle is wide, more than 90°, but less than 180°.
- Options: 95°, 180°, 70°
- 70° is too small, 180° is straight, this is slightly over 90°
- ✔ Answer: 95°

#### c)
- This angle is between 90° and 180°, but closer to 90°?
- Wait — look carefully: the angle appears to be about 110°, not 85° or 250°.
- Options: 85°, 250°, 110°
- 85° is acute, too small.
- 250° is reflex (greater than 180°), not possible here.
- The angle is obtuse, about 110°.
- ✔ Answer: 110°

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✔ Summary of Part 2:

| Letter | Answer |
|--------|--------|
| a) | 30° |
| b) | 95° |
| c) | 110° |

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✔ Final Answers:

#### Part 1:
a) 50°
b) 90°
c) 120°
d) 30°
e) 60°
f) 70°

#### Part 2:
a) 30°
b) 95°
c) 110°

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Let me know if you'd like a printable version or explanation for any specific part!