Understanding the Rectangle Dimensions
The dimensions of a rectangle consist of its length (L) and breadth (B). In this case, the relationship between the length and breadth is given as:
- Length (L) = 4 × Breadth (B)
This means that if you know the breadth, you can easily calculate the length.

Calculating the Perimeter
The formula for the perimeter (P) of a rectangle is:
- P = 2 × (Length + Breadth)
Substituting the relationship between length and breadth into the formula:
- P = 2 × (4B + B)
This simplifies to:
- P = 2 × (5B) = 10B

Conclusion
The perimeter of the rectangle can be expressed in terms of its breadth as follows:
- **If the breadth is known**, you can simply multiply it by 10 to find the perimeter.
- **For example**, if the breadth is 2 units, then:
- P = 10 × 2 = 20 units
Thus, the final formula for the perimeter of the rectangle is:
- **Perimeter (P) = 10 × Breadth (B)**

Summary
- Length (L) = 4 × Breadth (B)
- Perimeter (P) = 10 × Breadth (B)
This concise understanding allows you to determine the perimeter of a rectangle when its breadth is known, providing clarity and efficiency in calculations.