4th Grade Geometry - Free Printable

Let’s go through each angle one by one. Since we can’t use a real protractor here, I’ll estimate the angles based on how they look compared to common angles like 30°, 45°, 60°, 90°, etc.

Remember:
- A right angle (like the corner of a square) is 90°.
- An acute angle is less than 90°.
- An obtuse angle is more than 90° but less than 180°.
- We always measure from 0° — that means starting from the bottom line and going up to the other line.

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Angle 1)
This looks like it’s just a little bit more than 90°. Maybe around 100°? Let me think… if you imagine a straight line (180°), this is about halfway between 90° and 120°. Actually, looking again — it’s closer to 105°. But let’s be careful. Many worksheets like this use nice round numbers. It might be 100°.

Wait — actually, comparing to standard angles:
If 90° is straight up, this is tilted back a bit. Maybe 105°? Hmm. Let’s check others first and come back.

Actually, let’s try to be precise with estimation:

Angle 1: The vertical line would be 90°. This leans left a bit — so maybe 100°–110°. I’ll say 105° for now.

But wait — in many school worksheets, they often use multiples of 5 or 10. Let’s assume these are designed to be easy to measure. So perhaps:

Angle 1: Looks like 105° → but maybe it’s exactly 100°? Let’s hold off.

Actually, let’s do them all systematically.

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Angle 2)
This is an acute angle — clearly less than 90°. It looks like half of a right angle? No, half would be 45°. This looks bigger than 45° — maybe 50°? Or 60°?

Compare to 45° (halfway between horizontal and vertical). This is steeper — so maybe 50°? Or 55°?

Actually, it looks very close to 50°. Let’s say 50°.

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Angle 3)
Very small acute angle. Looks like maybe 20°? Or 25°? Definitely under 30°. If 45° is halfway, this is less than half of that — so maybe 25°.

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Angle 4)
Obtuse angle — greater than 90°. Looks like it’s about 135°? Because 135° is halfway between 90° and 180°. Yes — this looks like a perfect 135°. So 135°.

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Angle 5)
Acute angle — looks almost like 75°? Or 80°? It’s close to 90° but not quite. Maybe 75°.

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Angle 6)
Obtuse angle — looks like 150°? Because it’s 30° away from being flat (180°). Yes — if you imagine a straight line, this is only 30° short — so 150°.

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Now let’s double-check Angle 1. If Angle 4 is 135° and Angle 6 is 150°, then Angle 1 should be less than those. It’s only slightly over 90° — so maybe 100° is too low? Wait — no, 100° is reasonable.

Actually, let’s compare visually:

- Angle 1: ~105°
- Angle 2: ~50°
- Angle 3: ~25°
- Angle 4: ~135°
- Angle 5: ~75°
- Angle 6: ~150°

These are all multiples of 5 or 25 — which makes sense for a worksheet.

I think these are the intended answers.

Final Answer:
1) 105°
2) 50°
3) 25°
4) 135°
5) 75°
6) 150°