Plot the points (1,1), (2 ,-2) and (-1,-2) and check whether they are collinear or not

Plot the points (1,1), (2 ,-2) and (-1,-2) and check whether they are collinear or not. If not collinear, then determine the area of the figure.

Let us draw the coordinate axes XOX’ and YOY’ and then choose a suitable units of distance on the axes.
Let 1 cm = 1 unit.
Now, the points P(1,1), Q(2,-2)and R(-1,-2)can be plotted as shown below
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On joining these three points, we get three lines, so the given points do not lie on the same line.
So, the given points are not collinear and form a triangle. (2)
Now, draw a perpendicular line from P to RQ, i.e. PM.
image