Arithmetic Grade Five

Lesson One hundred and Sixty: Perimeter


Jill wants to measure her yard. She has a stick which she knows is five feet in length. She finds that her yard (which is rectangular) is 20 stick lengths long and 15 stick lenghts wide. What is the perimeter of Jill's yard in feet?

		stick lengths		feet
	length	    20		         100
	width	    15			  75

  In stick lengths, Jill's yard measures 20 by 15. In feet, therefore,
  her yard measures 100 by 75. Once we know the length and width of the
  yard in feet we can find the perimeter in the usual way:

	(100 + 75) * 2 = 350 feet

Jill has a basketball court in her backyard (which, as you would expect, is rectangular). She has a pole which is 8 feet long which she decides to use as her measuring device. She finds that the basketball court is three pole lengths wide and five pole lengths long. What is the perimeter of her basketball court in feet?

		pole lengths		feet
	length	    5			  40
	width	    3			  24

	Perimeter: (40 + 24) * 2 = 128 feet

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