## Elementary Geometry for College Students (7th Edition)

We call the point A at the origin, which is $(0,0)$. We call the length of a side of triangle ABCD length a. Thus, we obtain the lengths of the other sides using this information: $A: 0,0 \\ B: 0,2a \\ C: 2a,2a \\ D: 2a,0$
We call the point A at the origin, which is $(0,0)$. We call the length of a half of a side of square ABCD length a, for the book asks for a midpoint. Thus, we obtain the lengths of the other sides using this information: $A: 0,0 \\ B: 0,2a \\ C: 2a,2a \\ D: 2a,0$