Class 7 Maths worksheet on triangle properties, including classification by sides and angles.

Let's solve the worksheet step by step.

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Part 1: Classify each triangle as Scalene, Isosceles, or Equilateral

We classify triangles based on their side lengths:

- Scalene: All sides are of different lengths.
- Isosceles: Two sides are equal.
- Equilateral: All three sides are equal.

#### 1. Triangle ABC
- AB = 5 cm
- BC = 4 cm
- AC = 4.2 cm
→ All sides are different → Scalene

#### 2. Triangle PQR
- PQ = 6 cm
- PR = 6 cm
- QR = 8 cm
→ Two sides equal (PQ = PR) → Isosceles

#### 3. Triangle XYZ
- XY = 8 cm
- YZ = 8 cm
- XZ = 8 cm
→ All sides equal → Equilateral

#### 4. Triangle UVW
- UV = 4 cm
- VW = 8 cm
- UW = 7 cm
→ All sides different → Scalene

#### 5. Triangle LMN
- LN = 3 cm
- LM = 6.2 cm
- MN = 6.2 cm
→ Two sides equal (LM = MN) → Isosceles

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✔ Part 1 Answers:

1. ABC → Scalene
2. PQR → Isosceles
3. XYZ → Equilateral
4. UVW → Scalene
5. LMN → Isosceles

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Part 2: Classify each triangle as Acute, Right, or Obtuse

We classify based on angles:

- Acute: All angles < 90°
- Right: One angle = 90°
- Obtuse: One angle > 90°

#### 1. Triangle with a 90° angle (right angle symbol)
→ Has a 90° angle → Right

#### 2. Triangle with a 120° angle
→ One angle is greater than 90° → Obtuse

#### 3. Triangle with angles 70°, 60°, and 50°
- Check sum: 70 + 60 + 50 = 180° ✔️
- All angles < 90° → Acute

#### 4. Triangle with a 90° angle (right angle symbol)
→ Has a 90° angle → Right

#### 5. Triangle with angles 110°, 40°, 30°
- Sum: 110 + 40 + 30 = 180° ✔️
- One angle (110°) > 90° → Obtuse

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✔ Part 2 Answers:

1. → Right
2. → Obtuse
3. → Acute
4. → Right
5. → Obtuse

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✔ Final Answer Summary:

#### Types by Sides:
1. ABC → Scalene
2. PQR → Isosceles
3. XYZ → Equilateral
4. UVW → Scalene
5. LMN → Isosceles

#### Types by Angles:
1. → Right
2. → Obtuse
3. → Acute
4. → Right
5. → Obtuse

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✔ You can now fill in the blanks on the worksheet accordingly!