Advertisements
Advertisements
प्रश्न
A square lawn is bounded on three sides by a path 4 m wide. If the area of the path is `7/8` that of the lawn, find the dimensions of the lawn.
उत्तर
Let the side of the square lawn be x m.
Area of the square lawn = x2 m2
The square lawn is bounded on three sides by a path which is 4 m wide.
Area of outer rectangle = (x + 4)(x + 8) = x2 + 12x + 32
Area of path = x2 + 12x + 32 – x2 = 12x + 32
From the given information, we have:
`12x + 32 = 7/8 x^2`
`96x + 256 = 7x^2`
`7x^2 - 96x - 256 = 0`
`7x^2 - 112x + 16x - 256 = 0`
`7x(x - 16) + 16(7x + 16) = 0`
`(x - 16)(7x + 16) = 0`
`x = 16, (-16)/7`
Since, x cannot be negative.
So, x = 16 m.
Thus, each side of the square lawn is 16 m.
APPEARS IN
संबंधित प्रश्न
The sides of a right-angled triangle containing the right angle are 4x cm and (2x – 1) cm. If the area of the triangle is 30 cm2; calculate the lengths of its sides.
The hypotenuse of a right-angled triangle is 26 cm and the sum of other two sides is 34 cm. Find the lengths of its sides.
The hypotenuse of a right-angled triangle exceeds one side by 1 cm and the other side by 18 cm; find the lengths of the sides of the triangle.
The diagonal of a rectangle is 60 m more than its shorter side and the larger side is 30 m more than the shorter side. Find the sides of the rectangle.
The perimeter of a rectangle is 104 m and its area is 640 m2. Find its length and breadth.
The dimensions of a rectangular field are 50 m and 40 m. A flower bed is prepared inside this field leaving a gravel path of uniform width all around the flower bed. The total cost of laying the flower bed and gravelling the path at Rs. 30 and Rs. 20 per square metre, respectively, is Rs. 52,000. Find the width of the gravel path.
A farmer has 70 m of fencing, with which he encloses three sides of a rectangular sheep pen; the fourth side being a wall. If the area of the pen is 600 sq. m, find the length of its shorter side.
The perimeter of a square is numerically equal to its area. The perimeter of the square is ______.
If the width of the uniform shaded portion of x m; its area in terms of x is ______.
The length of a rectangle is 3 m more than its width. If its area is 180 m2; the length of the rectangle is ______.