SOLUTION: Prove that quadrilateral A(1,2), B(2,5), C(5,7), D(4,4) is a parallelogram by using slopes.

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Question 1173738: Prove that quadrilateral A(1,2), B(2,5), C(5,7), D(4,4) is a parallelogram by using slopes.
Found 2 solutions by greenestamps, ikleyn:
Answer by greenestamps(13216) (Show Source):
You can put this solution on YOUR website!

The problem tells you what to do; do it.

The quadrilateral is a parallelogram if both pairs of opposite sides are parallel.

Find the slopes of AB and CD and show they are equal; then do the same for sides AD and BC.

Answer by ikleyn(52915) (Show Source):
You can put this solution on YOUR website!
.

Calculate the slopes of opposite sides AB and DC and compare.

Calculate the slopes of opposite sides BC and AD and compare.

If the slopes are equal in pairs, then the quadrilateral is a parallelogram.

I hope you are able to do the rest without my help.