The area of a rectangular field is 2000 sq.m and its perimeter is 180m. form a quadratic equation by taking the length of the field as x and solve it to find the length and breadth of the field. the length and breadth are
Answers
Given :
The area of a rectangular field is 2000 sq meters
The perimeter of rectangular field = 180 meters
The length of field = x m
To Find :
The length and The breadth of field
Solution :
As The length of field = x meters
Let The breadth of field = y meters
Now,
∵ Area of a rectangular field = Length × breadth
So, 2000 m² = Length × breadth
Or, x × y = 2000 m² ..........1
Again
∵ Perimeter of rectangular field = 2 × ( length + breadth )
Or, 180 m = 2 × ( x + y )
Or, x + y =
∴ x + y = 90 meters ...........2
Now, ( x - y ) ² = ( x + y )² - 4 x y
= ( 90)² - 4 × 2000
= 8100 - 8000
= 100
∴ ( x - y ) ² = 100
Or, x - y =
i.e x - y = 10 ...............3
From eq 2 and eq 3
( x + y ) + ( x - y ) = 90 + 10
Or, ( x + x ) + ( y - y ) = 100
Or, 2 x + 0 = 100
∴ x = = 50 m
i.e Length of field = x = 50 m
Put the value of x into eq 2
∵ x + y = 90
Or, 50 + y = 90
Or, y = 90 - 50
∴ y = 40 m
i.e breadth of field = y = 40 m