Showing posts with label Perimeter. Show all posts
Showing posts with label Perimeter. Show all posts

Saturday, December 14, 2013

Two picture frames have the same area of 96 inches squared but different perimeters. What could the perimeters of the two frames be?

Both pictures must satisfy the equation:
A=96=l%5B1%5D%2Aw%5B1%5D=l%5B2%5D%2Aw%5B2%5D
So choosing valid values for any suitable pair of the four dimensions will produce different perimeters. For example:
l%5B1%5D=1, l%5B2%5D=2
results in
P%5B1%5D=194
P%5B2%5D=100
and so on...

Saturday, December 7, 2013

The area of a rectangle is 56 square meters. Find the length and width of the rectangle if it's length is 2 meters greater than it's width.

2(l+w)=56

so our first equation is...
1) l+w=28

comparing length and width...
l=w+2

so our second equation is...
2) l-w=2

system:
1) l+w=28
2) l-w=2
adding equations leads to
2l=30
so
l=15
w=13

Wednesday, October 23, 2013

a rectangle has one side equal to (2x+4)cm and a perimeter of (6x+4)cm what is the area of rectangle in terms of x

For convenience let's call the given side the length, so...
l=2x%2B4+ 
W are also given the perimeter...6x+4 and we for a rectangle, P=2%28l%2Bw%29+
therefore: 
2%28l%2Bw%29=6x%2B4+
so we have enough information to solve for w: 
2x%2B4%2Bw=3x%2B2
w=x-2 
Now we have enough information to solve for area.
A=l%2Aw
so
A=%282x%2B4%29%28x-2%29=%0D%0A2x%5E2-8+cm%5E2