Let's solve this step-by-step. The task is to
estimate the size of each angle,
identify its type, and write the
correct notation (using the three-letter format like ∠ABC).
---
🔍 Understanding Angle Types:
-
Acute angle: Less than 90°
-
Right angle: Exactly 90°
-
Obtuse angle: Between 90° and 180°
-
Reflex angle: Greater than 180° but less than 360°
---
We’ll go through each angle one by one.
---
1. Angle DEF
-
Visual Estimate: Looks smaller than a right angle, about 45°.
-
Type: Acute
-
Notation: ∠DEF
✔ Answer:
- Estimate:
45°
- Type:
ACUTE
- Notation:
∠DEF
---
2. Angle GIH
-
Visual Estimate: Very narrow, looks like about 20–30°.
-
Type: Acute
-
Notation: ∠GIH
✔ Answer:
- Estimate:
25°
- Type:
ACUTE
- Notation:
∠GIH
---
3. Angle JKL
-
Visual Estimate: Looks like it’s more than 90°, maybe around 120°.
-
Type: Obtuse
-
Notation: ∠JKL
✔ Answer:
- Estimate:
120°
- Type:
OBTUSE
- Notation:
∠JKL
---
4. Angle NMO
-
Visual Estimate: This is clearly greater than 180° — it goes around the point M. Looks like about 270°.
-
Type: Reflex
-
Notation: ∠NMO
✔ Answer:
- Estimate:
270°
- Type:
REFLEX
- Notation:
∠NMO
---
5. Angle PRQ
-
Visual Estimate: Looks like a standard "A" shape — close to 60°.
-
Type: Acute
-
Notation: ∠PRQ
✔ Answer:
- Estimate:
60°
- Type:
ACUTE
- Notation:
∠PRQ
---
6. Angle SUT
-
Visual Estimate: Looks slightly wider than 90° — about 100°.
-
Type: Obtuse
-
Notation: ∠SUT
✔ Answer:
- Estimate:
100°
- Type:
OBTUSE
- Notation:
∠SUT
---
7. Angle XWV
-
Visual Estimate: This has a small square at the corner — that means it's a
right angle.
-
Type: Right
-
Notation: ∠XWV
✔ Answer:
- Estimate:
90°
- Type:
RIGHT
- Notation:
∠XWV
---
8. Angle ZYA
-
Visual Estimate: This angle is open, but less than 90° — about 70°.
-
Type: Acute
-
Notation: ∠ZYA
✔ Answer:
- Estimate:
70°
- Type:
ACUTE
- Notation:
∠ZYA
---
9. Angle TPE
-
Visual Estimate: This angle is greater than 180° — it’s reflex. Looks like about 240°.
-
Type: Reflex
-
Notation: ∠TPE
✔ Answer:
- Estimate:
240°
- Type:
REFLEX
- Notation:
∠TPE
---
✔ Final Table Summary:
| Angle | Estimate | Type | Notation |
|-------|----------|----------|----------|
| DEF | 45° | ACUTE | ∠DEF |
| GIH | 25° | ACUTE | ∠GIH |
| JKL | 120° | OBTUSE | ∠JKL |
| NMO | 270° | REFLEX | ∠NMO |
| PRQ | 60° | ACUTE | ∠PRQ |
| SUT | 100° | OBTUSE | ∠SUT |
| XWV | 90° | RIGHT | ∠XWV |
| ZYA | 70° | ACUTE | ∠ZYA |
| TPE | 240° | REFLEX | ∠TPE |
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📝 Notes:
-
Estimates are approximate based on visual inspection. Actual measurements would require a protractor.
-
Notation always uses three letters, with the vertex in the middle.
-
Types are determined by degree range.
Let me know if you'd like a printable version or want to check any specific angle!
Parent Tip: Review the logic above to help your child master the concept of geometry worksheet angles.
