Question

In the centre of a rectangular plot of land of dimensions 120 m × 100 m, a rectangular portion is to be covered with trees so that the area of the remaining part of the plot is 10500 m². Find the dimensions of the area to be planted. Which social act is being discussed here? Give its advantages.

Answer 1

Let the width of the unplanted area be x m
Then, dimensions of area to be planted 

= (120 – 2x) and (100 – 2x)
= (120 – 2x) (100 – 2x) = 120 × 100 – 10500
⇒ 12000 – 440x + 4x² = 1500 or x² – 110x + 2625 = 0
⇒ (x – 75)(x – 35) = 0 or x = 75, 35

But x = 75 is not possible
x = 35

Thus, dimensions of area to be planted = (120 – 70) and (100 – 70) i.e., 50 m and 30 m.Afforestation is being discussed here. Planting more trees helps in reducing air pollution and make the environment clean and green.