[math-fun] Sin(angle)? No, angle(sign)

I threw an Aerobie down the street, trying to reach a certain road sign. Standing at the Aerobie, I was disappointed to see the face of the sign, across the street. But wait a minute, it's crooked! Eyeballing a perpendicular to the street, I'm a couple feet past the sign, dammit. Whoa, maybe roadsigns are twisted slightly clockwise on purpose? To exactly face traffic from where they first become visible? --rwg