I learned this trick from heureka.......we have 3 possibilities.....each one is found by adding two of the points and subtracting the remaining one.....so
Point 1 = (-3, 3), (2, 7), - (5, 1) = [ -3 + 2 -5, 3 + 7 -1] = [ -6, 9] = A
Here's the graph of this one: https://www.desmos.com/calculator/gn28jpviah
However....the points are out of order, here!!
Point 2 = (-3,3) + (5,1) - (2,7) = [ -3 +5 -2, 3 + 1 -7] = [-3, -3] = A
Here's the graph of this one : https://www.desmos.com/calculator/au5lye4htm
Point 3 = (2,7) + (5,1) - (-3, 3) = [ 2 + 5 + 3, 7 + 1 -3] = [ 10, 5] = A
This one is OK
Here's the graph of this one : https://www.desmos.com/calculator/fi07fvmpps
The points are ot of order here, too
Note that each different point forms a different paralelogram, but only the second one produces the points in the correct order.....!!!!
