Answer:
Step-by-step explanation:
+ The 2 diagonals AC et BD have their midpoint M.
+ We can find M like:
[tex]x_{M}=\frac{x_{A}+x_{C} }{2} = \frac{2+5}{2} =7/2\\\\ y_{M}=\frac{y_{A}+y_{C} }{2} = \frac{1+6}{2} =7/2\\[/tex]
So, we can find D like:
[tex]x_{D =2x_{M} -x_{B} = 2*(7/2) - 5 = 7 - 5= 2\\\y_{D} = 2y_{M} -y_{B} = 2*(7/2) - 1 = 7 - 1= 6\\[/tex]
The answer is D(2,6)
