Tenmarks Sucks! (Sorry for the strong language)

MISLEADING PICTURES AND WRONG ANSWERS

This is how an angle, measured in radians, of 5pi/6 should look:

And this is how the folks at Tenmarks drew it:

They made it larger than 180 degrees, instead of smaller than 180 degrees.  Big difference in Geometry!  

AND, they asked for the difference between arc BD and arc BC.  Now, every geometry student knows (and you would think the writer of this question would know too!) that arc BD is the small one, starting at B and going to clockwise to D. When you figure out what that one is, it turns out that it is also 5pi/6 !!  Of course, it doesn't look anything like the other one with the same measurement.  

BUT, it gets worse.  The answer they want is actually for the arc that starts at B and goes counterclockwise, through C, to D.  Every geometry student knows that you call that one:  arc BCD. Otherwise, there would no way to differentiate the two.

BAD, BAD, BAD.