To calculate the percentage increase in the area of the rectangle, we first need to determine the original area and the new area after increasing the dimensions.
1. **Original Dimensions**: The original length is 40m and the original breadth is 25m.
2. **Original Area**: The area of a rectangle is calculated by multiplying its length and breadth. So, the original area is:
Original Area = Length × Breadth
Original Area = 40m × 25m = 1000m²
3. **New Dimensions**: If both the length and breadth are increased by 15m:
New Length = 40m + 15m = 55m
New Breadth = 25m + 15m = 40m
4. **New Area**: The new area can now be calculated:
New Area = New Length × New Breadth
New Area = 55m × 40m = 2200m²
5. **Increase in Area**: To find the increase in area, subtract the original area from the new area:
Increase in Area = New Area – Original Area
Increase in Area = 2200m² – 1000m² = 1200m²
6. **Percentage Increase**: Now, we can find the percentage increase in area using the formula:
Percentage Increase = (Increase in Area / Original Area) × 100%
Percentage Increase = (1200m² / 1000m²) × 100% = 120%
Thus, the percentage increase in the area of the rectangle is 120%.