Question

Please help I don’t understand This lesson is called coordinate that makes the rectangle/parallelogram

Answer 1

The first step is plot the given points A,B,C to visualize the problem and where D is going to be.

Now, given the definition of a parallelogram, the line DC must have the same slope of BA because both lines al parallel. Similarly, the line BC is parallel to AC. Given this information, it can be shown that the x-coordinate difference between D and C must be the same as the x-coordiante difference between B and A.

Given the point B (-9,1) and A (-2,4), the x-coordinate difference is:

`-9-(-2)=-7`

Hence, this -7 is also the x-coordinate difference between C and D. Given C (-1,-5), the x-coordiante of D must be:

`-1-7=-8`

In the same way, the y-coordinate difference between A (-2,4) and B (-9,1) is:

`4-1=3`

And this y-coordinate difference must be the same between C (-1,-5) and D. Hence the y-coordinate of D is:

`-5-3=-8`

ANSWER

Finally, the coordinates of point D are (-8,-8)