Question

The area of a rectangular field is 48 m² and one of its sides is 6 m. How long will a lady take to cross the field diagonally at the rate of 20 m/minute?

Answer 1

Given, the area of a rectangular field is 48 m² and one side of the rectangle = 6 m

∴ Area of a rectangle = Length × Breadth

⇒ 48 = 6 × Breadth

⇒ Breadth = 8 m

In ΔACD, ∠D = 90°

So, it is a right-angled triangle.

By using Pythagoras theorem, we have

(AC)² = (AD)² + (DC)²

⇒ (AC)² = (6)² + (8)²

⇒ (AC)² = 36 + 64

⇒  `AC = sqrt(100)`

∴ AC = 10 m

Time taken by lady to cross the field diagonally at rate of 20 m/min = `"Distance"/"Speed"`

= `10/20`

= `1/2` min or 30 sec