Re: concave and rounds
Pam Niedermayer - Austin, TX
>Concave:
Etymology: Middle English, from Middle French, from Latin concavus, from com- + cavus hollow -- more at CAVE
1 : hollowed or rounded inward like the inside of a bowl
2 : arched in : curving in -- used of the side of a curve or surface on which neighboring normals to the curve or surface converge and on which lies the chord joining two neighboring points of the curve or surface
Rounds are planes that are rounded on their cutting edge to create a concave surface.
If you can remember those two definitions, everything else can be figured out until it all comes naturally.
Pam