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Sun 4 Jan, 2015 06:31 pm
A fence is to be constructed around a rectangular field. The boards are 12 feet in length. The fence is 4 boards in height.
Field is 660 feet wide and contains 20 acres.
Calculate number of boards needed.
What is known:
A fence is to be constructed around a field rectangular in shape.
Boards used are 12 feet in length.
The fence is 4 boards in height.
Field is 660 feet in width and contains 20 acres.
Want to know:
Number of boards needed.
Let B = number of boards.
Each section of fence is 48 feet of boards.
20 acres = 871,200 square feet.
871,200 / 12 = 68433.33 feet of boards.
68433.33 / 12 = 5702.775 = 5703 boards.
Where did I make the errors ?
@Randy Dandy,
Randy Dandy wrote:
Let B = number of boards.
Each section of fence is 48 feet of boards.
20 acres = 871,200 square feet.
871,200 / 12 = 68433.33 feet of boards. Here is the error.
You need to compute the perimeter of the area. You know it is a rectangle, one side is 660 feet and the area is 871200 sq. ft.
Once you have the perimeter you can compute the number of boards using four boards for every twelve feet of perimeter.
@engineer,
871200 / 660 = 1320
1320 / 12 = 110
110 * 4 = 440 boards.
Where did I miscalculate ?
@Randy Dandy,
You've got the length and width of the rectangular field. A fence goes around the edges of the field.
RAP
@Randy Dandy,
Yes, you only did one side. Do the other three and you are done.
660 + 660 + 1320 + 1320 = 3960 ft. - perimeter.
3960 / 12 = 330 sections.
330 * 4 boards per section = 1320 boards.
Correct ?
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