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Slope is gradient and the formula for this is Y2-Y1/X2-X1
so in the case of the line AB it will be X1=-1 & Y1=2 and X2=2 & Y2=4 so plug those into the formul and you get (4-2)/(2--1) = 2/(2+1) ie 2/3 so gradient/slope = 2/3 and so you just have to do that for the other lines BC, DC and AD and to find it it is a parrallelogram just check if the gradient of AB and DC are equal and if the gradient/slope of BC and AD are equal if they all are then it is a parallelogram and your reason is because because parallel lines have the same gradient/slope
Hello dgen,
Have you tried finding the slope of a line before? Use the following formula:
The slope of a line between 2 points $\displaystyle (x_1, y_1) \ \ and \ \ (x_2, y_2)$ is given by
$\displaystyle m=\frac{y_2-y_1}{x_2-x_1}$
Use the pairs of points you are given to find the slopes of AB, BC, CD, and DA.
To determine if the figure is a parallelogram, see if the slopes of the opposite sides are the same. If they are, this means the segments are parallel. And if opposite sides of a quadrilateral are parallel, the quadrilateral is a parallelogram.
You can do this. Give it a shot.