4. The length of a rectangle exceeds the width by 2 cm. If the diagonal is 10 cm long, find the width of the rectangle.
Answers
Answer:
Let the breadth be x
so the length will be x+8
area of the rectangle=240cm²
∵area of rectangle=length*breadth
∴240=(x)(x+8)
240=x²+8x
x²+8x-240=0
x²+20x-12x-240=0
x(x+20)-12(x+20)=0
(x+20)(x-12)=0
so x=-20 or x=12
∵The dimensions cannot be negative
∴x=12
length=20cm
breadth=12cm
➡.The length of a rectangle exceeds the width by 2 cm.
➡ the diagonal is 10 cm
➡ width of the rectangle. = ?
Let the length of the rectangle be x cm,
According to question :-
⭐ if length of a rectangle exceeds the width by 2 cm, the width be x + 2 cm
10 = x² + (x + 2)²
10 = x² + x² + 4x + 4
10 = 2x² + 4x + 4
2x² + 4x -6 = 0
Divide by '2' in above equation
x² + 2x - 3 = 0
x² +(3-1)x - 3 = 0
x² + 3x - x - 3 =0
x(x+3)-1(x+3)
(x-1)(x+3)
x = 1 & x = -3
⭐ Length can't be negative
so x = 1
Length of the rectangle = 1cm
and breadth be 1+3=4 cm