Students match protractor readings to the correct angle measurements in this educational worksheet.

Let’s go through each protractor one by one and read the angle correctly.

Remember:
- If the angle opens to the right, use the bottom scale (starts at 0° on the right).
- If the angle opens to the left, use the top scale (starts at 0° on the left).
But actually, a better way is: look at where the first ray points — if it points to 0° on the bottom, read the bottom numbers. If it points to 0° on the top, read the top numbers.

Actually, even simpler:
Look at which side the angle starts from (the baseline ray), and follow the scale that begins at 0° on that side.

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Problem 1)
The angle has one ray pointing to the left (at 180° on bottom, or 0° on top) and the other ray going up-left.
Since the baseline is on the left, we should use the top scale (which starts at 0° on the left).
Follow the top scale: the second ray points to 45°.
✔ So, 1) → 45°

Wait — let me double-check.
In problem 1, the pink arrows show: one arrow pointing left along the base, and another pointing up-left. The angle between them is measured from the left baseline. On the top scale (inner numbers starting from left), the moving ray hits 45°. Yes.

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Problem 2)
Baseline is on the right (arrow pointing right). So we use the bottom scale (starts at 0° on right).
The other ray goes up-left. Following the bottom scale from right (0°), we go counter-clockwise? Wait — no.

Actually, protractors are read based on direction of opening.

Better method:
Look at the two rays. One is fixed on the horizontal line. See which end of the horizontal line the angle starts from.

In #2: The angle starts from the right side (ray pointing right = 0° on bottom scale). Then the other ray goes up to the left. We follow the bottom scale from right to left? No — wait, the bottom scale increases from right to left? Actually, no.

Standard protractor:
Bottom scale: 0° on right, increases to 180° on left.
Top scale: 0° on left, increases to 180° on right.

So for #2:
Ray 1: pointing right → so start at 0° on bottom scale.
Ray 2: pointing up-left → on the bottom scale, that would be... let's see: from right (0°), moving counter-clockwise, the ray hits 140°? But that can’t be because the angle looks acute.

Wait — I think I’m confusing myself.

Let me try this:

In #2, the angle is formed with the baseline on the right, and the other ray is in the upper half. Since the baseline is on the right, we use the bottom scale, but we read from right to left? Actually, no — the bottom scale reads 0° at right, then 10, 20, ..., up to 180° at left.

But the ray in #2 is pointing to about 140° on the bottom scale? That would make it obtuse, but visually it looks like an acute angle.

Wait — maybe I have it backwards.

Alternative approach:
Always look at the smaller angle unless specified otherwise. But here, all angles shown are less than 180°, and we just need to match.

Let me look at the position:

In #2: The moving ray is between 30° and 40° on the top scale? Let’s check:

If I use the top scale (0° on left), then from left, 0°, 10°, 20°, 30°, 40° — the ray is at 36°? Yes! Because 36° is one of the options.

And since the angle opens to the left? No — in #2, the baseline is on the right, but the angle is measured inside, so perhaps we should use the scale that gives the correct measure.

Actually, standard rule:
Place the protractor so that the vertex is at center, and one ray is at 0°. Then read where the other ray crosses.

In #2: If we consider the ray pointing right as 0°, then rotating counter-clockwise, the other ray is at 144°? That doesn't match any option.

Wait — perhaps the angle is measured clockwise? No, protractors are usually read counter-clockwise from the 0° mark.

I think I made a mistake.

Let me re-express:

For each diagram, identify which scale to use based on where the "starting" ray is.

In #1: Starting ray is on the left (pointing left), so use top scale (0° on left). Moving ray is at 45° on top scale → 45°.

In #2: Starting ray is on the right (pointing right), so use bottom scale (0° on right). Now, moving ray is going up-left. On the bottom scale, from right (0°), moving counter-clockwise, the degrees increase: 10, 20, 30, ... up to 180 on left. The ray in #2 is pointing to approximately 144° on bottom scale? But 144° is not an option. Options are 45, 36, 119, 70, 140.

140 is close. Is it 140°?

Let me count: from right, 0°, then each big tick is 10°, small ticks 1°. From right, moving counter-clockwise: after 130°, next is 140°, and the ray is exactly at 140°? Looking at the image description — in #2, the ray is between 140 and 150? No, let's think differently.

Perhaps for #2, since the angle is acute, and the ray is closer to the vertical, it might be 36° if we use the other scale.

I recall that sometimes students get confused between inner and outer scales.

Let me try this trick:
The sum of the two readings (inner and outer) at any point is 180°. So if you're unsure, pick the one that makes sense for the angle size.

In #2, the angle looks acute — less than 90°. So it must be either 36° or 45° or 70°. 45° is taken by #1. 70° is larger. 36° is possible.

How to get 36°? If we use the top scale: from left, 0°, then the ray is at 36°? But in #2, the baseline is on the right, so why would we use top scale?

Unless — the angle is measured from the left? But the arrow shows the baseline on the right.

I think there's a better way: look at the direction of the angle.

In #2, the two rays form an angle that opens upwards, and the baseline is horizontal to the right. The other ray is in the second quadrant. The angle from the positive x-axis (right) to the ray is 180° minus something.

Perhaps it's easier to estimate:

In #2, the ray is very close to the 30-40 degree mark on the top scale. And 36° is an option. Also, in many worksheets, they design it so that you use the scale that matches the acute angle.

Let me check online or recall standard practice.

Upon second thought, in most school worksheets, when the angle is drawn with the baseline on the right, and the other ray in the upper half, if the angle is acute, you might still use the top scale if it's measured from the left, but that doesn't make sense.

I found a reliable method:
Align the protractor so that the 0° is on the side where the angle starts. In #2, the angle starts from the right, so 0° on right. Then the other ray is at how many degrees? If it's at 140° on the bottom scale, that would be the reflex angle, but we want the smaller angle, which is 180° - 140° = 40°, but 40° is not an option.

36° is close to 40°, so perhaps it's 36°.

Let's look at the exact position. In the image, for #2, the ray is at the 36th degree mark if we count from the left on the top scale. And since the angle is acute, and 36° is an option, likely that's it.

Moreover, in some protractors, the scales are labeled such that you choose the scale where the number is less than 90 for acute angles.

So for #2, it's 36°.

Similarly, for #3: baseline on right, other ray up-right, so acute angle. Using bottom scale from right, it should be around 70°? Let's see.

In #3, the ray is at 70° on the bottom scale? From right, 0°, then 70° is where the ray is. Yes, and 70° is an option.

For #4: baseline on left, other ray up-left, so using top scale, it should be 140°? From left, 0°, then 140° is on the top scale? Top scale from left: 0° to 180° on right, so 140° would be near the right end. In #4, the ray is at 140° on the top scale? Let's see: from left, 0°, 10,20,...,140° is 40° from the right, which matches the position.

For #5: baseline on right, other ray up-left, so using bottom scale, it should be 119°? From right, 0°, then 119° is between 110 and 120.

Let me list them properly:

After careful analysis:

1) Angle opens to the left, use top scale: reads 45° → matches 45°

2) Angle opens to the right, but the acute angle is measured; however, looking at the ray, on the top scale it's at 36° (since from left, 36°), and since the angle is acute, we take 36° → matches 36°

3) Angle opens to the right, use bottom scale: from right, the ray is at 70° → matches 70°

4) Angle opens to the left, use top scale: from left, the ray is at 140° → matches 140°

5) Angle opens to the right, use bottom scale: from right, the ray is at 119° → matches 119°

Yes, that makes sense with the options.

Confirming:

- 1) 45°
- 2) 36°
- 3) 70°
- 4) 140°
- 5) 119°

All options are used once.

Final Answer:
1) 45°
2) 36°
3) 70°
4) 140°
5) 119°