algebra

posted by .

give the demensions of rectangles with the perimeters of 70 feet and length-to-width ratios of 3 to 4, 4 to 5, and 1 to 1.


Ok, the perimeter is 70 and perimeter = 2(length + width)
The ratio is length:with=3:4 so length = (3/4)width
70 = 2(length + width) =2((3/4)width +
width)
So 35 = (7/4)width
Can you finish it off?
If the ratio is 4:5 then 35=((4/5)width + width)
If it's 1:1 then 35 = 2*length = 2*width
Can you finish it off now?


I'm sorry I havn't done this in 20 years my son is in 7th grade doing 8th grade work and I guess the teacher expects the student to know this stuff. He has given no direction to the kids. Thank you for all your help. I will have to get a teaching book on Algebra so I can teach my child.


Ok. This is introductory algebra so you should have no trouble finding sources to help. If you look at the Jump box above you'll find lessons that cover this material on Jiskha.


Thank You, Thank you


You're welcome
Feel free to have your son post questions too. There are plenty of people helping here.


Let the width-to-length ratio be r. I am calling "length" the longest side, so r is less than or equal to 1.

Let a be the longest side length. The shortest side length is then a*r.

The perimeter is
70 = 2a (1 + r)
35 = a (1+r)
a = 35/(1+r)

Solve for a, using r values of 3/4, 4/5 and 1
When r = 3/4, a = 35/(7/4) = 20
The short side will then be 3/4 of 20, or 15. You do the others

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. algebra

    suppose the length of a rectangle increases,but the perimeter remains at 70 feet. How does the width change?
  2. algebra

    What is the width of a rectangle with a perimeter of 70 feet if its length is 1 foot?
  3. basic geometric

    10. a rectangle has width the same as a side of a square whose perimeter is 20m. the length of the rectangle is 9m. find the perimeter of this rectangle. 34. The width of a rectangular picture is one-half the length. The perimeter …
  4. basic geometry

    A rectangle has width the same asa a side of a square whose perimeter is 20m.the length of the rectangle is 9m. Find the perimeter of this rectangle. 34. The with of a rectangular picture is on-half the length . The perimeter of the …
  5. geometric

    The perimeter of a rectangular carpet is 70feet. The with is three -fourths the length .Find the width. 38. The length of a rectagular room is six times as the width . The perimeter 84 yards. find the width. 39. The width of a rectangle …
  6. math

    Recognize that rectangles that have the same area can have different perimenters. Do rectangles with the same area necessarily have the same perimeter?
  7. Algebra

    I need help with my daughters homework. I know a little bit of algebra but it has been about 15 years since I have done it. She switched schools recently and there was a learning gap in the schools. The problem is: give the demensions …
  8. math

    what would the dimensions of a retangle be whose perimeter is 50(P=50)inches when the length is 2x-5 ane the width is unknown The width must be 25 - (2x-5) = 30-2x, since the sum of the length and width must be half the perimeter. …
  9. Math ( Algebra 1 )

    Two rectangles have the same width. The length of one is 2 feet longer than the width. The length of the other is 4 feet longer than the width. The larger rectangle has 8 more square feet than the smaller. What is the width of the …
  10. Algebra

    The perimeter of a rectangular garden is 35 feet. The length of the garden is 1 foot more than 2 times its width. Write an equation to represent the perimeter of the garden in terms of its width (w). What are the length and width of …

More Similar Questions