By using the concept of slope, show that the points (– 2, – 1), (4, 0), (3, 3) and (– 3, 2) vertices of a parallelogram.
To Prove: Given points are of Parallelogram.
Explanation: Let us Assume that we have points, A (– 2, – 1), B(4, 0), C(3, 3) and D(– 3, 2), are joining the sides as AB, BC, CD, and AD.
The formula used: The slope of the line, m =
Now, The slope of Line AB, mAB =
mAB =
The slope of BC, mBC =
mBC =
Now, The slope of Line CD, mCD =
mCD =
The slope of AD, mAD =
mAD =
Here, We can see that, mAB = mCDand mBC = mAD
i.e, AB CD and BC
AD
We know, If opposite side of a quadrilateral are parallel that it is a parallelogram.
Hence, ABCD is a Parallelogram.