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#1 2007-01-22 08:12:08

jxharmon
Member
Registered: 2007-01-08
Posts: 104

is figure a parallelogram or rectangle

the points on graph are (0,3),(2,0),(-1,-2),(-3,1)

is this the way to work this  m=1-(-2)/-3-(-1) =-1/2   m=0-3/2-0=-3/2

this would be a rectangle  would like to know if this is correct

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#2 2007-01-22 12:15:08

pi man
Member
Registered: 2006-07-06
Posts: 251

Re: is figure a parallelogram or rectangle

There are 4 lines that make up this rectangle/parallelogram.   The lines and their slopes are:

(0,3) to (2,0) with a slope of (3-0) / (0-2) = -3/2
(2,0) to (-1,-2) with a slope of (0-(-2)) / (2-(-1)) = 2/3
(-1,-2) to (-3,1) with a slope of (-2-1) / (-1-(-3) = -3/2
(-3,1) to (0,3) with a slope of (1-3) / (-3-0) = 2/3

The lines with equal slopes are parallel to each other.   For this figure to be a rectangle, the lines that intersect must be perpendicular to each other which implies that they have slopes which are the negative inverses of each other.   The negative inverse of -3/2 is 2/3.   So it is a rectangle.

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