Making a trapezoidal shape for vinyl cutting

Hello Everyone,

I am the newest of the newbies here, trying to use Corel Draw to make the artwork for my Roland Stika vinyl cutter. 

My first project is very simple - a trapedzoid with 1/8" thick solid lines.  I can draw it using a variety of methods (Bezier, freehand, welding corners), but there is always some little flaw that affects the final drawing - for example, combining the freehand lines left a  cutout step at the outside each corner, where I am thinking the center of the line intersected the center of the other line.

For this project, I need crisp inside and outside intersections.  If anyone can point me in the right direction I would sure appreciate it!  I have played around with the program for a couple of days and I am feel like I am missing something very fundamental.

Thanks in advance for your time

Kurt