A parallelogram has vertices A(0, 4), B(2, 2), C(4, 4), and D(2,6). Is this parallelogram a square? Explain why or why not.

If we take the adjacent side AD and DC  and work out their slopes we get 

AD = (6-4)/(2-0)  = 1 and DC has slope (6-4)/(2-4)  = -1 . This shows that the angle between the 2 lines is 90 degrees so it looks like  this is a square.

Step-by-step explanation:

A square is a special parallelogram that has 4 congruent sides and 4 right angles. Using the distance formula, you can prove that all 4 sides have a length of the square root of 8. This proves the parallelogram is a rhombus. Next, find the slope of all 4 sides.  The slopes of sides AB and CD are –1, and the slopes of sides BC and DA are 1. Since adjacent sides have opposite reciprocal slopes they are perpendicular and form right angles. This proves that parallelogram ABCD is a square.

Step-by-step explanation:

On edg 2020 enjoy it.I hope it will help.

687.09 dollars       happy now

step-by-step explanation: 6870

1857 times .63 equals 1169.91 subtract that from 1857 you get 687.09