Worksheet for identifying angles as acute, obtuse, right, or straight based on visual representation.

Let’s go through each angle one by one and decide if it’s acute, obtuse, right, or straight.

Remember:
- Acute = less than 90° (small, sharp angle)
- Right = exactly 90° (like the corner of a square)
- Obtuse = more than 90° but less than 180° (wide angle)
- Straight = exactly 180° (looks like a straight line)

We’ll look at each numbered angle visually:

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1) Looks smaller than a right angle → Acute

2) Looks wider than a right angle → Obtuse

3) Very small angle → Acute

4) Wide angle, not straight → Obtuse

5) Looks like a right angle? Wait — actually, it’s slightly less → Acute
*(Check: The two lines form a narrow V — definitely under 90°)*

Wait — let me double-check #5. Looking again: the angle opens to about 70–80 degrees? Still acute.

Actually, looking carefully — in many worksheets, #5 is drawn as obtuse. Let me re-evaluate based on standard visual cues.

Hold on — better to be systematic.

Let me list them with careful observation:

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Revised step-by-step:

Ex) Given as *obtuse* — that’s our example.

1) Small angle → Acute
2) Wide open → Obtuse
3) Tiny angle → Acute
4) Clearly wider than 90° → Obtuse
5) This one looks like it might be close to 90°, but actually, from the drawing, it's less → Acute? Or maybe right?

Wait — I think I need to be precise.

Looking at common versions of this worksheet (since this is a known Common Core sheet), here are the correct answers based on standard key:

But since we must solve visually without external keys, let’s use logic:

Imagine a clock:

- At 3:00 → right angle (90°)
- Between 12 and 3 → acute
- Between 3 and 6 → obtuse
- 6:00 → straight

Now apply that mentally.

1) Like 1 o’clock → acute
2) Like 4 o’clock → obtuse
3) Like 12:30 → very acute
4) Like 5 o’clock → obtuse
5) Like 2 o’clock → acute
6) Almost straight, but bent up → obtuse (close to 180, but not quite)
7) Small triangle tip → acute
8) Also small → acute
9) Looks like 4 o’clock → obtuse
10) Very flat, almost straight → but still bent → obtuse? Wait — no, it’s very small! Actually, it’s a tiny angle → acute
Wait — #10: two short lines forming a very narrow angle → acute

11) Right angle? Looks like L-shape → right
12) Corner of rectangle → right
13) Flat curve downward → straight? No, it’s curved dotted line — wait, the angle itself: points left and right, vertex in middle → straight angle (180°) → straight
14) Looks like 1 o’clock → acute
15) Like 4 o’clock → obtuse
16) Triangle pointing up → acute
17) Straight horizontal line → straight
18) Semicircle dotted — angle is along straight line → straight
19) Looks like 2 o’clock → acute
20) Looks like 4 o’clock → obtuse

Wait — let’s fix inconsistencies.

Better approach: group by type.

List all 20:

1. Acute
2. Obtuse
3. Acute
4. Obtuse
5. Acute
6. Obtuse (almost straight)
7. Acute
8. Acute
9. Obtuse
10. Acute (very small)
11. Right (clear L shape)
12. Right (corner)
13. Straight (flat line with vertex in middle)
14. Acute
15. Obtuse
16. Acute
17. Straight (horizontal line)
18. Straight (dotted semicircle implies 180°)
19. Acute
20. Obtuse

Double-check tricky ones:

#6: Two long lines, wide angle — yes, obtuse
#10: Very narrow — acute
#11: Perfect L — right
#12: Same — right
#13: Points going opposite directions — straight
#17: Same — straight
#18: Dotted arc shows half circle — straight angle
#20: Wide — obtuse

Yes, this seems consistent.

Final Answer:

1. acute
2. obtuse
3. acute
4. obtuse
5. acute
6. obtuse
7. acute
8. acute
9. obtuse
10. acute
11. right
12. right
13. straight
14. acute
15. obtuse
16. acute
17. straight
18. straight
19. acute
20. obtuse