good app for simple graphics with text to be used in an MS word do***ent

I tried using Fireworks for this, but the text always seemed blurry
when im****ting the images to MS Word.  I am creating simple images to
illustrate various mathematic and geometric principles such as
30-60-90 triangles, parallel lines, finding the area of a circle and
the like.  So the pictures are very simple, but I need some text in
them.  They need no color.  What would be the best and easiest
software for this?  Would freehand work?  I already know Fireworks, so
the easier the transition, the better.  Any really simple program that
can make 300 dpi images would be fine too though.

Thanks