Problem Overview:
The task involves using a protractor to draw angles of specific measures and then classifying each angle as
acute,
right, or
obtuse. The worksheet provides the correct answers, but we will explain how to solve it step by step.
---
Key Concepts:
1.
Acute Angle: An angle that measures less than 90°.
2.
Right Angle: An angle that measures exactly 90°.
3.
Obtuse Angle: An angle that measures more than 90° but less than 180°.
---
Solution Explanation:
#### Step 1: Understand the Protractor
- A protractor is a semicircular tool used to measure angles.
- It has two scales (inner and outer), each ranging from 0° to 180°.
- To measure an angle:
- Place the center of the protractor at the vertex of the angle.
- Align one ray with the 0° mark on the protractor.
- Read the angle measurement where the second ray intersects the protractor scale.
#### Step 2: Draw Each Angle
For each given angle measure, follow these steps:
1. Draw a horizontal ray (initial side) starting from the vertex.
2. Use the protractor to measure the specified angle.
3. Draw a second ray from the vertex through the measured point on the protractor.
#### Step 3: Classify Each Angle
After drawing each angle, classify it based on its measure:
- If the angle is less than 90°, label it as
acute.
- If the angle is exactly 90°, label it as
right.
- If the angle is greater than 90° but less than 180°, label it as
obtuse.
---
Detailed Solutions for Each Angle:
1.
125°
- Measure 125° using the protractor.
- The angle is greater than 90°, so it is
obtuse.
2.
130°
- Measure 130° using the protractor.
- The angle is greater than 90°, so it is
obtuse.
3.
45°
- Measure 45° using the protractor.
- The angle is less than 90°, so it is
acute.
4.
90°
- Measure 90° using the protractor.
- The angle is exactly 90°, so it is
right.
5.
140°
- Measure 140° using the protractor.
- The angle is greater than 90°, so it is
obtuse.
6.
75°
- Measure 75° using the protractor.
- The angle is less than 90°, so it is
acute.
7.
90°
- Measure 90° using the protractor.
- The angle is exactly 90°, so it is
right.
8.
100°
- Measure 100° using the protractor.
- The angle is greater than 90°, so it is
obtuse.
---
Final Answer:
The classification of each angle is already provided in the answer key:
-
125°: obtuse
-
130°: obtuse
-
45°: acute
-
90°: right
-
140°: obtuse
-
75°: acute
-
90°: right
-
100°: obtuse
Thus, the solution matches the provided answer key.
$$
\boxed{\text{See classifications above}}
$$
Parent Tip: Review the logic above to help your child master the concept of measuring angles worksheet.
