SOLUTION: Given ABCD is a parallelogram with vertices A (-1, -4), B (1,2) and C (3, 3), find the equation of the line BD

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: Given ABCD is a parallelogram with vertices A (-1, -4), B (1,2) and C (3, 3), find the equation of the line BD      Log On


   

Question 1110391: Given ABCD is a parallelogram with vertices A (-1, -4), B (1,2) and C (3, 3), find the equation of the line BD
Answer by Cromlix(4381) About Me  (Show Source):
You can put this solution on YOUR website!
Hi there,
First find the gradient of BC
y2 - y1/x2 - x1 = 3 - 2/3 - 1 = 1/2
Now AD will have the same gradient (parallelogram's sides)
Coordinates for point D (x, y)
Gradient of AD y - (-4)/x - (-1) = y + 4/x + 1
y + 4/x + 1 = 1/2: y = -3 x = 1
D(1, -3)
As D and B have the same x coordinate
Equation of line BD => x = 1
Hope this helps :-)