Perimeter worksheet for students to practice calculating the perimeter of different shapes by adding the lengths of all sides.

To solve the problem of finding the perimeter of each shape, we need to add up the lengths of all the sides of each shape. Let's go through each shape step by step.

1. Rectangle (9 cm × 4 cm)

- Sides: 9 cm, 4 cm, 9 cm, 4 cm
- Perimeter: \( 9 + 4 + 9 + 4 = 26 \) cm

2. Triangle (3 mm, 11 mm, 15 mm)

- Sides: 3 mm, 11 mm, 15 mm
- Perimeter: \( 3 + 11 + 15 = 29 \) mm

3. Square (5 mm × 5 mm)

- Sides: 5 mm, 5 mm, 5 mm, 5 mm
- Perimeter: \( 5 + 5 + 5 + 5 = 20 \) mm

4. Trapezoid (8 m, 8 m, 3 m, 5 m)

- Sides: 8 m, 8 m, 3 m, 5 m
- Perimeter: \( 8 + 8 + 3 + 5 = 24 \) m

5. Irregular Pentagon (7 cm, 2 cm, 2 cm, 7 cm, 5 cm)

- Sides: 7 cm, 2 cm, 2 cm, 7 cm, 5 cm
- Perimeter: \( 7 + 2 + 2 + 7 + 5 = 23 \) cm

6. Equilateral Triangle (6 km × 6 km × 6 km)

- Sides: 6 km, 6 km, 6 km
- Perimeter: \( 6 + 6 + 6 = 18 \) km

7. Right Triangle (3 km, 4 km, 5 km)

- Sides: 3 km, 4 km, 5 km
- Perimeter: \( 3 + 4 + 5 = 12 \) km

8. Rhombus (4 cm × 4 cm × 4 cm × 4 cm)

- Sides: 4 cm, 4 cm, 4 cm, 4 cm
- Perimeter: \( 4 + 4 + 4 + 4 = 16 \) cm

Final Answers:

1. Rectangle: \( \boxed{26} \) cm
2. Triangle: \( \boxed{29} \) mm
3. Square: \( \boxed{20} \) mm
4. Trapezoid: \( \boxed{24} \) m
5. Pentagon: \( \boxed{23} \) cm
6. Equilateral Triangle: \( \boxed{18} \) km
7. Right Triangle: \( \boxed{12} \) km
8. Rhombus: \( \boxed{16} \) cm

These are the perimeters of the given shapes. Each calculation involves simply adding the lengths of all the sides of the respective shape.