Question 1128500
Using slopes, find the fourth vertex of a parallelogram
 If (7,-1), (-3,1) and (-5,5) are its consecutive vertices
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Label the points:
A(7,-1), B(-3,1) and C(-5,5)
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Find the slope of AB, and the slope of BC
Call the 4th point D

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The slope of AD will be the same as the slope of BC

The slope CD will be the same as the slope of AB
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Find the equations of the lines AD and CD.
The intersection is the point D