Classifying triangles based on their sides: equilateral, isosceles, and scalene.

To classify each triangle based on its sides, we look at how many sides are equal:

- Equilateral: All 3 sides are the same length.
- Isosceles: Exactly 2 sides are the same length.
- Scalene: All 3 sides are different lengths.

Since this is a visual worksheet and no measurements are given, we must estimate by eye which triangles have matching side lengths.

Let’s go one by one:

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1a. Red triangle — looks like all sides are different → scalene

1b. Blue triangle — two sides look about the same (left and bottom), third is shorter → isosceles

1c. Blue triangle — all sides clearly different lengths → scalene

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2a. Green triangle — all sides appear different → scalene

2b. Red triangle — tall and narrow; left and right sides look equal, base is shorter → isosceles

2c. Green triangle — all sides different → scalene

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3a. Blue triangle — two sides look equal (top-left and top-right), base is shorter → isosceles

3b. Red triangle — all sides seem different → scalene

3c. Green triangle — two sides look equal (bottom and right), left is longer → isosceles

Wait — let me double-check 3c. Actually, looking again: the green triangle in 3c has one long side (left), and the other two look similar? Hmm… maybe not. Let’s be careful.

Actually, in 3c: the bottom side and the right side look roughly equal, and the left side is longer → still isosceles.

But wait — maybe I’m misjudging. Let’s compare with others.

Alternatively, perhaps 3c is scalene? Let’s hold that thought and check consistency.

Actually, let’s re-evaluate all using a consistent method: if it *looks* like two sides match, call it isosceles. If none match, scalene. Equilateral would be very obvious — none of these look equilateral.

Looking again:

None of the triangles have all three sides obviously equal → so no equilateral triangles in this set.

Now, for isosceles: which ones have two sides that look equal?

- 1b: yes → isosceles
- 2b: yes → isosceles
- 3a: yes → isosceles
- 3c: actually, looking closely — the two shorter sides might be equal? Or maybe not. Let’s say it’s scalene to be safe? Wait — no, in 3c, the bottom and right sides look similar in length, left is longer → isosceles.

But let’s count how many should be isosceles vs scalene.

Total triangles: 12

If we assume none are equilateral, then each is either isosceles or scalene.

Let me list them again carefully:

Row 1:
- 1a: scalene
- 1b: isosceles
- 1c: scalene

Row 2:
- 2a: scalene
- 2b: isosceles
- 2c: scalene

Row 3:
- 3a: isosceles (two equal sides)
- 3b: scalene (all different)
- 3c: let’s say isosceles (two sides look equal)

Row 4:
- 4a: blue triangle — very skinny, all sides different → scalene
- 4b: green triangle — two sides look equal? Left and bottom? Maybe → isosceles
- 4c: red triangle — all sides different → scalene

Wait — 4b: the green triangle. The left side and the bottom side look similar? Or is the right side equal to one of them? Actually, it looks like the two longer sides are equal → isosceles.

So let’s tally:

Isosceles: 1b, 2b, 3a, 3c, 4b → that’s 5

Scalene: 1a, 1c, 2a, 2c, 3b, 4a, 4c → that’s 7

Total: 12 → good.

But is 3c really isosceles? Let me visualize again.

In 3c: the triangle is pointing up-left. The side from top to bottom-right looks long. The side from bottom-right to bottom-left looks medium. The side from bottom-left to top looks medium too? Maybe those two are equal → yes, isosceles.

Similarly, 4b: the green triangle — the two sides that form the “V” at the bottom look equal → isosceles.

Okay, confident now.

Final classification:

1a: scalene
1b: isosceles
1c: scalene

2a: scalene
2b: isosceles
2c: scalene

3a: isosceles
3b: scalene
3c: isosceles

4a: scalene
4b: isosceles
4c: scalene

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Final Answer:
1a: scalene
1b: isosceles
1c: scalene
2a: scalene
2b: isosceles
2c: scalene
3a: isosceles
3b: scalene
3c: isosceles
4a: scalene
4b: isosceles
4c: scalene