Educational worksheet for identifying acute and obtuse angles.

Let’s go step by step to solve this problem.

We are given a worksheet about acute and obtuse angles.

First, let’s remember the definitions from the top of the page:

- A right angle is like the corner of a square — it measures exactly 90°.
- An obtuse angle is greater than a right angle (so more than 90°).
- An acute angle is less than a right angle (so less than 90°).

Now, we look at each labeled angle in the diagram and decide whether it’s acute or obtuse.

Let’s go one by one:

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Angle a: Looks very narrow — definitely less than 90° → Acute

Angle b: This one opens wide — looks bigger than 90° → Obtuse

Angle c: Very pointy, small opening → Acute

Angle d: Wide open, clearly more than 90° → Obtuse

Angle e: Small, sharp angle → Acute

Angle f: Also small and sharp → Acute

Angle g: Narrow, not wide → Acute

Angle h: Slightly wider but still under 90°? Let’s check — actually, looking closely, it seems to be just under 90° → Acute

Wait — let me double-check angle h. If you imagine a right angle (like an L shape), angle h is smaller than that → yes, Acute

Angle i: This one is wide — definitely over 90° → Obtuse

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So now, let’s list them:

✔ Acute angles: a, c, e, f, g, h
✔ Obtuse angles: b, d, i

Wait — did I miss any? Let’s count the labels: a through i → that’s 9 angles total.

We have:
- Acute: a, c, e, f, g, h → 6 angles
- Obtuse: b, d, i → 3 angles

That adds up to 9. Good.

But let’s recheck angle h again — sometimes these can trick you. Angle h is drawn as a slanted line with a small arc — it’s definitely less than 90°. Yes.

Also, angle f — same thing, very small.

Angle g — also small.

Angle e — tiny.

Angle c — very pointy.

Angle a — narrow.

All good.

Obtuse ones: b, d, i — all visibly wider than a right angle.

Perfect.

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Final Answer:

Which of the angles are acute?
a, c, e, f, g, h

Which of the angles are obtuse?
b, d, i