GrannieAnnie

Find yourself a half round plastic compass. Use it to draw a prefect circle. A circle is 360 degrees, so divide that by

5 which will give you a 72 degree arc for each side of a perfect pentagon. Use the degrees marked on your plastic compass to indicate where the lines ought to intersect. (72, then 144, the flip over and do again)

I am assuming you are wanting a perfectly equal pentagon. if you're looking for a pentagon to start a crazy quilt, you don't want perfect, and all you'd need to do is make a figure with 5 sides.