Question

For parallelogram ABCD, A(0, 0), B(a, b), and D(c, 0) are three of its vertices. Find the coordinates of C in terms of a, b, c.

Answer 1

https://media.glynlyon.com/g_geo_2012/9/groupi84.gif

Answer 2

I'm not sure what it is, it seems like it should be simple, the choices I have are

1) (c, b)

2) (a + c, b)

3) (a, b + c)