Classify triangles by their angles: identify acute, obtuse, or right triangles based on angle markings.

Let's solve the problem step by step.

Task:

Classify each triangle as acute, obtuse, or right based on its angles.

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Definitions:

- Right triangle: Has one 90° angle (marked with a small square).
- Obtuse triangle: Has one angle greater than 90°.
- Acute triangle: All three angles are less than 90°.

We’ll examine each triangle in the image and determine its classification.

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Step-by-step Analysis of Each Triangle:

1. Top-left triangle
- Has a square symbol at one angle → this is a 90° angle.
- ✔ Right triangle

2. Top-right triangle
- Has a square symbol at one angle → 90° angle.
- ✔ Right triangle

3. Middle-left triangle
- No right angle symbol, no obvious large angle.
- Looks like all angles are less than 90°.
- ✔ Acute triangle

4. Middle-center triangle
- No right angle symbol.
- One angle appears to be greater than 90° (widely open).
- ✔ Obtuse triangle

5. Middle-right triangle
- Has two hash marks on sides — but that indicates equal sides (isosceles), not angles.
- But there’s no right angle symbol, and it looks like all angles are less than 90°.
- However, check if any angle is wide: seems all acute.
- ✔ Acute triangle

6. Bottom-left triangle
- Has a square symbol → 90° angle.
- ✔ Right triangle

7. Bottom-center triangle
- Has two hash marks on two sides → isosceles.
- But no right angle, and one angle is clearly larger than 90° (the top one).
- ✔ Obtuse triangle

8. Bottom-right triangle
- Has three hash marks on sides → equilateral?
- But wait: three hash marks on sides suggest all sides equal → equilateral triangle.
- In an equilateral triangle, all angles are 60° → all acute.
- ✔ Acute triangle

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Final Answers:

Label each triangle:

1. Top-left → Right
2. Top-right → Right
3. Middle-left → Acute
4. Middle-center → Obtuse
5. Middle-right → Acute
6. Bottom-left → Right
7. Bottom-center → Obtuse
8. Bottom-right → Acute

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✔ Summary:

| Triangle | Classification |
|---------|----------------|
| Top-left | Right |
| Top-right | Right |
| Middle-left | Acute |
| Middle-center | Obtuse |
| Middle-right | Acute |
| Bottom-left | Right |
| Bottom-center | Obtuse |
| Bottom-right | Acute |

This completes the worksheet!