Hello, vixsta101!
Did you make a sketch?
You are told that $\displaystyle ABCD$ is a square in $\displaystyle R^2$ and that it contains the origin $\displaystyle (0,0).$
This means that the origin in inside the square.
You also know that vertex $\displaystyle A$ has coordinates $\displaystyle (\text{}1,\text{}3)$
and vertex B has coordinates $\displaystyle (4,\text{}2).$
What are the coordinates of the remaining vertices $\displaystyle C$ and $\displaystyle D$? Code:

 (3,3)
*    +      o  *
:  C :
D o(2,5)  :
:  :
:  :
:  :
+++
: O :
:  :
:  B:
:  o(4,1)
: A  :
*  o          *
(1,3)

We can "walk" our way through this . . .
Going from vertex $\displaystyle A$ to vertex $\displaystyle B$, we move 5 units right and 1 unit up.
Going from vertex $\displaystyle B$ to vertex $\displaystyle C$, we move 1 unit left and 5 units up. .(Why?)
. . Hence: .$\displaystyle C(3,3)$
Going from vertex C to vertex D, we move 5 units left and 1 unit down.
. . Hence: .$\displaystyle D(\text{}2,2)$