Question

B is the midpoint of AC and E is the midpoint of BD. if A(-9,-4), C(-1, 6), and E(-4, -3) find coordinates of D

Answer 1

Answer: The coordinates of D are (-3, -7).

Step-by-step explanation:

First, we need to find the coordinates of B. In order to do that, take the average of the two points that make up the segment which are A and C.

Average of x's: -9 + -1 = -10/2 = -5

Average of y's: -4 + 6 = 2/2 = 1

Therefore, the coordinates of B are (-5, 1). Coordinates are always (x,y).

Now we can find D by noting that the E will be the average of B and D. So we can use the average equation to determine the value of D.

Average of the x's:

(B + D)/2 = E

(-5 + D)/2 = -4

-5 + D = -8

D = -3  

Average of the y's:

(B + D)/2 = E

(1 + D)/2 = -3

1 + D = -6

D = -7

The coordinates of D are (-3, -7).