Grade 5 Geometry worksheet on estimating angles with visual examples and answer choices.

Problem: Estimating Angles

The task is to estimate the size of the angles shown in the images and choose the best option from the given choices.

Solution:

#### Step 1: Understand the problem
We need to estimate the size of each angle visually and select the closest option from the provided choices. Here are the key points:
- Acute angles are less than 90°.
- Right angles are exactly 90°.
- Obtuse angles are greater than 90° but less than 180°.
- Straight angles are exactly 180°.
- Reflex angles are greater than 180° but less than 360°.

#### Step 2: Analyze each angle

##### Angle 1:
- The angle appears to be slightly more than 45° but less than 90°.
- Choices: a. 45°, b. 85°, c. 5°, d. 135°
- Best estimate: b. 85°

##### Angle 2:
- The angle appears to be close to a straight line, which is 180°.
- Choices: a. 180°, b. 135°, c. 120°, d. 170°
- Best estimate: a. 180°

##### Angle 3:
- The angle appears to be very small, close to 0° but not quite.
- Choices: a. 15°, b. 75°, c. 105°, d. 90°
- Best estimate: a. 15°

##### Angle 4:
- The angle appears to be obtuse, closer to 135°.
- Choices: a. 25°, b. 75°, c. 155°, d. 135°
- Best estimate: d. 135°

##### Angle 5:
- The angle appears to be acute, close to 45°.
- Choices: a. 105°, b. 85°, c. 150°, d. 45°
- Best estimate: d. 45°

##### Angle 6:
- The angle appears to be obtuse, close to 135°.
- Choices: a. 120°, b. 135°, c. 90°, d. 140°
- Best estimate: b. 135°

##### Angle 7:
- The angle appears to be obtuse, close to 130°.
- Choices: a. 75°, b. 110°, c. 130°, d. 85°
- Best estimate: c. 130°

##### Angle 8:
- The angle appears to be acute, close to 25°.
- Choices: a. 5°, b. 10°, c. 15°, d. 25°
- Best estimate: d. 25°

##### Angle 9:
- The angle appears to be very small, close to 15°.
- Choices: a. 10°, b. 15°, c. 20°, d. 25°
- Best estimate: b. 15°

##### Angle 10:
- The angle appears to be acute, close to 65°.
- Choices: a. 65°, b. 75°, c. 55°, d. 50°
- Best estimate: a. 65°

Final Answers:

1. b. 85°
2. a. 180°
3. a. 15°
4. d. 135°
5. d. 45°
6. b. 135°
7. c. 130°
8. d. 25°
9. b. 15°
10. a. 65°

Boxed Final Answer:

\[
\boxed{b, a, a, d, d, b, c, d, b, a}
\]