The area of a rectangular playground of a school is 300 m². The length of the playground is 1 m more than twice its breadth.

(a) Find the length and breadth of the playground.

(b) By what percentage should the length of the playground be decreased so that it is reduced to a square?



Answer :

Sure! Let's solve this step by step.

## Part (a)
### Given:
- The area of the rectangular playground is 300 m².
- The length of the playground [tex]\( l \)[/tex] is 1 meter more than twice its breadth [tex]\( b \)[/tex].

This translates to:
[tex]\[ l = 2b + 1 \][/tex]
[tex]\[ \text{Area} = l \times b = 300 \][/tex]

### Step-by-step solution:

1. Substitute the expression for [tex]\( l \)[/tex] into the area equation:
[tex]\[ (2b + 1) \times b = 300 \][/tex]

2. Simplify and solve the quadratic equation:
[tex]\[ 2b^2 + b - 300 = 0 \][/tex]

3. Solve the quadratic equation using factoring, the quadratic formula, or another method:
[tex]\[ b = 12 \][/tex]

4. Substitute the value of [tex]\( b \)[/tex] back into the length equation to find [tex]\( l \)[/tex]:
[tex]\[ l = 2(12) + 1 \][/tex]
[tex]\[ l = 25 \][/tex]

### Answer for Part (a):
- Breadth of the playground [tex]\( b = 12 \)[/tex] meters
- Length of the playground [tex]\( l = 25 \)[/tex] meters

## Part (b)
### Given:
- We want to convert the rectangular playground (keeping the area the same) to a square.

### Step-by-step solution:

1. Find the side length of the square. Since the area of the playground is to remain 300 m², the side length [tex]\( s \)[/tex] of the square is:
[tex]\[ s = \sqrt{300} \][/tex]
[tex]\[ s \approx 17.32 \][/tex]

2. Calculate the decrease needed in the length:
[tex]\[ \text{Length decrease} = l - s \][/tex]
[tex]\[ \text{Length decrease} = 25 - 17.32 \][/tex]
[tex]\[ \text{Length decrease} \approx 7.68 \][/tex]

3. Determine the percentage decrease in length:
[tex]\[ \text{Percentage decrease} = \left( \frac{\text{Length decrease}}{l} \right) \times 100 \][/tex]
[tex]\[ \text{Percentage decrease} = \left( \frac{7.68}{25} \right) \times 100 \][/tex]
[tex]\[ \text{Percentage decrease} \approx 30.72 \% \][/tex]

### Answer for Part (b):
- The length of the playground should be decreased by approximately 30.72% to convert it to a square with the same area.

Thus, these detailed steps lead to the results:
- Breadth of the playground: 12 meters
- Length of the playground: 25 meters
- Side length of the equivalent square: 17.32 meters
- Percentage decrease in length: approximately 30.72%