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If the length and breadth of a rectangle...

If the length and breadth of a rectangle are doubled then its perimeter is

A

tripled

B

doubled

C

made half

D

none of these

Text Solution

AI Generated Solution

The correct Answer is:
To solve the problem, we need to determine how the perimeter of a rectangle changes when both its length and breadth are doubled. Let's break this down step by step. ### Step-by-Step Solution: 1. **Understand the formula for the perimeter of a rectangle**: The perimeter (P) of a rectangle is given by the formula: \[ P = 2 \times (L + B) \] where \(L\) is the length and \(B\) is the breadth of the rectangle. 2. **Identify the new dimensions**: If the length and breadth are doubled, the new length \(L'\) and new breadth \(B'\) can be expressed as: \[ L' = 2L \quad \text{and} \quad B' = 2B \] 3. **Calculate the new perimeter**: Substitute the new dimensions into the perimeter formula: \[ P' = 2 \times (L' + B') = 2 \times (2L + 2B) \] 4. **Simplify the expression**: Factor out the common term: \[ P' = 2 \times (2(L + B)) = 4 \times (L + B) \] 5. **Relate the new perimeter to the old perimeter**: Recall the original perimeter: \[ P = 2 \times (L + B) \] Now, we can express the new perimeter in terms of the old perimeter: \[ P' = 4 \times (L + B) = 2 \times (2 \times (L + B)) = 2 \times P \] 6. **Conclusion**: Therefore, when the length and breadth of a rectangle are doubled, the new perimeter is: \[ P' = 2P \] This means the new perimeter is double the original perimeter. ### Final Answer: The perimeter is **double**. ---
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