| 
 
 
| Question 1139124:  Show that the points (-1, -3) (-2, 0) (1, 6) and (2, 3) are the vertices of a parallelogram.
 Answer by Boreal(15235)
      (Show Source): 
You can put this solution on YOUR website! Draw this and look at the two lines  with negative slopes (-1, -3) and (-2, 0), then at (1, 6) and (2, 3).  Their slopes are -3 and -3, so those are parallel. Look at the other two lines with positive slopes
 (-1, -3) and (2, 3) have slope 2
 and (-2, 0) and (1, 6) have slope 2
 Look at the length of each line is sqrt(10) and sqrt(10) for the nearly vertical ones and sqrt(45) and sqrt(45) for the others
 The opposite lines are parallel; two pairs of parallel lines, each pair the same length.  This is a parallelogram.
 y+3=-3(x-1)
 y=-3x
 y=2x+4
 y-3=-3(x-2); y=-3x+3
 y-3=2(x-3); y=2x-3
 
  
 | 
  
 | 
 |