The diagonal of a rectangular field is 60 metres more than the shorter side. If the longer side is 30 metres more than the shorter side, find the sides of the field.
Answers
Let us say, the shorter side of the rectangle be x m.
Then, larger side of the rectangle = (x + 30) m
As given, the length of the diagonal is = x + 30 m
Therefore,
⇒ x^2 + (x + 30)^2 = (x + 60)^2
⇒ x^2 + x^2 + 900 + 60x = x^2 + 3600 + 120x
⇒ x^2 – 60x – 2700 = 0
⇒ x^2 – 90x + 30x – 2700 = 0
⇒ x(x – 90) + 30(x -90) = 0
⇒ (x – 90)(x + 30) = 0
⇒ x = 90, -30
However,
side of the field cannot be negative.
Therefore,
the length of the shorter side will be 90 m.
and the length of the larger side will be (90 + 30) m = 120 m.
- The diagonal of a rectangular field is 60 metres more than the shorter side.
- The longer side is 30 metres more than the shorter side.
To find :-
- The sides of the field
Solution :-
Let shorter side be x m
diagonal = ( x + 60) m
longer side = (x + 30) m
In right ∆ ABC
(AC)² = (AB)² + (BC)²
➝ (x + 60)² = (x)² + (x + 30)²
➝ (x)² + 2 × x × 60 + (60)² = x² + (x)² + 2 × x × 30 + (30)²
➝ x² + 120x + 3600 = x² + x² + 60x + 900
➝ x² + 60x + 900 - 120x - 3600 = 0
➝ x² - 60x - 2700 = 0
➝ x² - 90x - 30x - 2700 = 0
➝ x(x - 9) + 30(x - 90) = 0
➝ (x - 90) ( x + 30) = 0
Now,
➝ (x - 90) = 0
➝ x = 0 + 90
➝ x = 90
Then,
➝ (x + 30) = 0
➝ x = 0 - 30
➝ x = -30
Hence,the side of the field cannot be negative so, the length of the shorter side will be 90m.
and length of longer side will be (x + 30) = (90 + 30) = 120 m.