The perimeter of a rectangular lawn is 66 meters. The area is 260 square meters. What are the dimensions of the lawn?

meters by
meters

1 answer

Let the length of the lawn be \( l \) meters and the width be \( w \) meters.

We know the formulas for the perimeter and area of a rectangle:

  1. The perimeter \( P \) is given by: \[ P = 2l + 2w = 66 \]

    Simplifying this gives: \[ l + w = 33 \quad \text{(1)} \]

  2. The area \( A \) is given by: \[ A = lw = 260 \quad \text{(2)} \]

Now, we can solve these two equations.

From equation (1), we can express \( l \) in terms of \( w \): \[ l = 33 - w \]

Now, substitute \( l \) in equation (2): \[ (33 - w)w = 260 \] Expanding this gives: \[ 33w - w^2 = 260 \] Rearranging to form a standard quadratic equation: \[ w^2 - 33w + 260 = 0 \]

Now we can use the quadratic formula to solve for \( w \): \[ w = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} \] Here, \( a = 1 \), \( b = -33 \), and \( c = 260 \).

Calculating the discriminant: \[ b^2 - 4ac = (-33)^2 - 4 \cdot 1 \cdot 260 = 1089 - 1040 = 49 \]

Now we can find \( w \): \[ w = \frac{33 \pm \sqrt{49}}{2} = \frac{33 \pm 7}{2} \]

Calculating the two possible values:

  1. \( w = \frac{40}{2} = 20 \)
  2. \( w = \frac{26}{2} = 13 \)

Thus, the possible dimensions of the lawn are:

  1. If \( w = 20 \), then \( l = 33 - 20 = 13 \).
  2. If \( w = 13 \), then \( l = 33 - 13 = 20 \).

Therefore, the dimensions of the lawn are:

\[ \text{20 meters by 13 meters} \]

Final answer: 20 meters by 13 meters