I'm very new to this software. This could be a bug or it could be a spec I'm not setting properly:
I draw a circle in "Design". "Snap to Grid" is turned off. I draw a line extending from the center down to the perimeter. The box shows 90 degrees. I draw a second line from the center to the perimeter, this time at 72 degrees, or 18 degrees from my original line. I choose "select" and then go to the "Measure" menu. I click the "measure" tool and use Ctrl to select my two line segments and they read 18.01 degrees instead of 18.
I can duplicate this effect over and over again (with varying degrees of differences).
What is going wrong?