co-ord. geom qs (no. 3!) (1 Viewer)

[Smeegen999]

if:
A = (1,5)
B = (4,2)
C = (2,-3)

find the coordinates of D such such that ABCD is a parallelogram

i put D as (x,y) and tried substitution methods and it didn't work! :S Can somenone help me?

 

[zingerburger]

The way I always did these questions was to make a number plane and plot the points. You can then figure out D pretty easily. I know it kind of sounds like a cheat way out, but I always seemed to get full marks doing it that way, I think.

 

[Studentleader]

if:
A = (1,5)
B = (4,2)
C = (2,-3)

find the coordinates of D such such that ABCD is a parallelogram

i put D as (x,y) and tried substitution methods and it didn't work! :S Can somenone help me?

A parrallelogram quadrilateral with opposite sides parallel and equal

If so, the gradient of A to B = the Gradient of C to D.
Find the distance between A and B then apply to C to find D? (do some linear equation if you wish)

 

[me121]

if:
A = (1,5)
B = (4,2)
C = (2,-3)

find the coordinates of D such such that ABCD is a parallelogram

i put D as (x,y) and tried substitution methods and it didn't work! :S Can somenone help me?

well i would roughly plot the points. now you can calculate the two gradients of the sides, then you can get the equation of these lines because you know where they pass through, then you can solve simultaneous to find the point of intersection, ie. D.

 

[Studentleader]

well i would roughly plot the points. now you can calculate the two gradients of the sides, then you can get the equation of these lines because you know where they pass through, then you can solve simultaneous to find the point of intersection, ie. D.

Yeah without a doubt the best thing to do would be to graph it, your idea is probally alot better by the sounds of it.

 

[Caitlin63]

im with student leader, that's how you do it