I'll solve each volume problem step by step. Let me work through all six problems carefully.
Problem (1): Rectangular Prism
- Dimensions: 10.4 m × 4.8 m × 9 m
- Volume = length × width × height
- V = 10.4 × 4.8 × 9
- V = 49.92 × 9
- V = 449.28 m³
Problem (2): Rectangular Prism
- Dimensions: 42 ft × 9 ft × 18 ft
- Volume = length × width × height
- V = 42 × 9 × 18
- V = 378 × 18
- V = 6,804 ft³
Problem (3): Triangular Prism
- Base of triangle: 8 cm
- Height of triangle: 15 cm
- Length of prism: 12 cm
- Volume = (½ × base × height) × length
- V = (½ × 8 × 15) × 12
- V = (4 × 15) × 12
- V = 60 × 12
- V = 720 cm³
Problem (4): Trapezoidal Prism
- Parallel sides: 4 in and 6 in
- Height of trapezoid: 3 in
- Length of prism: 9 in
- Area of trapezoid = ½(a + b)h = ½(4 + 6)(3) = ½(10)(3) = 15 in²
- Volume = area of base × length
- V = 15 × 9
- V = 135 in³
Problem (5): Cylinder
- Diameter: 5 cm, so radius = 2.5 cm
- Height: 18 cm
- Volume = πr²h
- V = 3.14 × (2.5)² × 18
- V = 3.14 × 6.25 × 18
- V = 19.625 × 18
- V = 353.25 cm³
Problem (6): Cylinder
- Radius: 16 m
- Height: 18 m
- Volume = πr²h
- V = 3.14 × (16)² × 18
- V = 3.14 × 256 × 18
- V = 803.84 × 18
- V = 14,469.12 m³
Final Answer:
(1) 449.28 m³
(2) 6,804 ft³
(3) 720 cm³
(4) 135 in³
(5) 353.25 cm³
(6) 14,469.12 m³
Parent Tip: Review the logic above to help your child master the concept of volume and surface area worksheets grade 7.