SOLUTION: If A(3,6) and C(-1,2) are two vertices of a rhombus ABCD, then find the equation of straight line that lies along the diagonal BD.

Algebra ->  Linear-equations -> SOLUTION: If A(3,6) and C(-1,2) are two vertices of a rhombus ABCD, then find the equation of straight line that lies along the diagonal BD.      Log On


   



Question 1188643: If A(3,6) and C(-1,2) are two vertices of a rhombus ABCD, then find the equation of straight line that lies along the diagonal BD.
Answer by ikleyn(52782) About Me  (Show Source):
You can put this solution on YOUR website!
.
If A(3,6) and C(-1,2) are two vertices of a rhombus ABCD, then find the equation of straight line that lies along the diagonal BD.
~~~~~~~~~~~~~~~~~~~



                The STRATEGY


(1)  First find an equation of the line AC;

(2)  then find the midpoint of the segment AC;

(3)  then find an equation of the perpendicular line passing through this midpoint.


                IMPLEMENTATION


(1)  To find an equation of the line AC, first find its slope:  m = %282-6%29%2F%28-1-3%29 = %28-4%29%2F%28-4%29 = 1.

     Hence, an equation of the line AC is  y-6 = 1*(x-3),  or  y-6 = x-3,  or  y - x = 3.


(2)  The midpoint of the segment AC is (1,4)  (the mean values for each pair of co-named coordinates).


(3)  The perpendicular line to AC is  x + y = const = 1 + 4 = 5.


ANSWER.  The sough equation is  x + y = 5  (or any other equation, equivalent to it . . . )

Solved.