Question

15. Using the concept of slope, show that the vertices (1 , 2), (-2 , 2), (-4 , -3)
and (-1, -3) taken in order form a parallelogram.

Answer 1

In the attachments I have answered this problem.

Formula:

1.Slope of line joining the points (x1, y1)
and (x2, y2) is

(y2 - y1) / (x2 -x1)

2. Two lines are Parallel if and only if their slopes are equal.

Let the given points be A, B, C and D

We have to prove that ABCD is a Parallelogram.

It is enough to prove that
AB is Parallel to CD
BC is Parallel to AD

See the attachments for detailed solution