Protractor Practice worksheet for measuring angles.

Let’s go through each angle one by one. We’ll estimate the measure of each angle based on how it looks — since we don’t have a real protractor here, we’ll use common angle benchmarks:

- A right angle (like the corner of a square) = 90°
- A straight line = 180°
- Half of a right angle = 45°
- Angles smaller than 90° are acute
- Angles bigger than 90° but less than 180° are obtuse

We’ll look at each box and give our best estimate.

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Top Left Angle:
This is an acute angle — looks like it’s about halfway between 0° and 90°, maybe a bit more. Let’s say 45°.

Wait — actually, looking again, it might be a little wider than 45°. Maybe 50°? But in many worksheets, this kind of angle is often drawn as exactly 45° or 60°. Let me think… if you imagine splitting a right angle into two equal parts, that’s 45°. This looks very close to that. I’ll go with 45°.

Actually — let’s compare it to others. The next one down is clearly smaller. So maybe this one is 50°? Hmm. To be safe and realistic for a student worksheet, these are usually nice round numbers. Let’s assume standard angles used in practice sheets: 30°, 45°, 60°, 90°, 120°, etc.

Looking again — top left: opens up nicely, not too sharp. Likely 45°.

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Top Right Angle:
This is an obtuse angle — bigger than 90°. It looks like it’s just past 90°, maybe around 100°–110°. If you picture a right angle (90°), this is opened a little more. Common value? Probably 100° or 110°. Let’s say 100° — it doesn’t look super wide.

Wait — actually, comparing to bottom left which is also obtuse, this one seems slightly less open. Bottom left looks closer to 120°. So top right might be 100°.

But let’s check another way: if you extend the horizontal ray backward, the angle from there would be 80°, so the actual angle is 180° - 80° = 100°. Yeah, that makes sense. So 100°.

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Middle Left Angle:
Very small acute angle — much narrower than the top left one. Looks like about half of 45°, so maybe 30°. That’s a common angle in worksheets. Yes, 30° feels right.

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Middle Right Angle:
Perfect L-shape — that’s a classic right angle. Definitely 90°.

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Bottom Left Angle (third row, left):
Obtuse angle — wider than 90°. Looks like it’s about 1/3 past 90° toward 180°. So 90° + 30° = 120°. Or maybe 110°? Let’s see — if you split the space between 90° and 180° into three parts, each is 30°. This looks like it’s one part over — so 120°.

Yes, 120° is a good fit.

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Bottom Right Angle (third row, right):
Tiny acute angle — even smaller than the middle left one. Middle left was ~30°, this looks like half of that — so 15°? But worksheets usually use 15°, 30°, 45°, etc. This could be 20°, but more likely 15° or 30°? Wait — no, it’s definitely smaller than 30°. Let’s say 15°.

Actually, looking again — it’s very narrow. In many such worksheets, they use 20° or 25° sometimes, but 15° is possible. Alternatively, maybe it’s 20°? I think 20° is safer — still small, but not extremely tiny. Let’s go with 20°.

Wait — let’s reconsider all together for consistency.

Common angles in protractor practice:
Acute: 30°, 45°, 60°
Right: 90°
Obtuse: 100°, 110°, 120°, 135°, 150°

So let’s assign:

Top Left: 45°
Top Right: 100°
Middle Left: 30°
Middle Right: 90°
Third Row Left: 120°
Third Row Right: 20°? Not common. Maybe 25°? Still not standard. Perhaps it’s 30°? No, it’s visibly smaller than middle left.

Alternatively — maybe third row right is 15°? Some worksheets do include 15°.

But let’s look at last two:

Fourth Row Left: Obtuse, looks similar to top right but maybe a bit wider — perhaps 110°?

Fourth Row Right: Very wide obtuse — almost flat. Looks like 150° or 160°. Since 180° is straight, and this is just shy of that — probably 150°.

Let me list them again with final estimates:

1. Top Left: Acute, medium size → 45°
2. Top Right: Obtuse, slightly over 90° → 100°
3. Middle Left: Small acute → 30°
4. Middle Right: Right angle → 90°
5. Third Row Left: Obtuse, clearly wider → 120°
6. Third Row Right: Very small acute → 20° (or 15° — but I'll pick 20° as compromise)
7. Fourth Row Left: Obtuse, looks like 110° → 110°
8. Fourth Row Right: Almost straight → 150°

Wait — fourth row left: the angle is formed by a line going up-left and one going right. The opening is large — actually, it might be 120°? No, compared to third row left which is 120°, this one looks a bit smaller. Maybe 110° is okay.

Fourth row right: the angle is very wide — the two rays are almost opposite. So 150° is reasonable.

But let’s double-check third row right — it’s really small. Maybe it’s 25°? I think for simplicity and matching typical worksheets, we should stick to multiples of 5 or 10.

Final decision:

After careful visual estimation and considering standard worksheet angles:

- Top Left: 45°
- Top Right: 100°
- Middle Left: 30°
- Middle Right: 90°
- Third Row Left: 120°
- Third Row Right: 20° ← though uncommon, it fits visually; alternatively 25°, but I’ll keep 20°
- Fourth Row Left: 110°
- Fourth Row Right: 150°

Actually — let’s adjust third row right to 25°? No, better to use rounder numbers. Maybe it’s 30°? But it’s visibly smaller than middle left which we called 30°. Contradiction.

Perhaps middle left is 40°? No, that’s not standard.

Another idea: maybe third row right is 15° — some advanced worksheets include that.

I recall that in many such printable worksheets, the smallest angle shown is often 20° or 25°. Let’s choose 20° for now.

Similarly, fourth row left — let’s call it 110°, and fourth row right 150°.

To confirm, let’s write them in order as they appear in the grid:

Grid layout (row by row, left to right):

Row 1:
- Box 1: 45°
- Box 2: 100°

Row 2:
- Box 3: 30°
- Box 4: 90°

Row 3:
- Box 5: 120°
- Box 6: 20°

Row 4:
- Box 7: 110°
- Box 8: 150°

Yes, this seems consistent with visual estimation and typical educational materials.

Final Answer:
45°, 100°, 30°, 90°, 120°, 20°, 110°, 150°