topic Object making in AC 9,Page 66. in Libraries & objects

Object making in AC 9,Page 66.

Anonymous — Mon, 16 Jun 2008 15:33:08 GMT

Hi,

In the pics above the author is explaining how to get the curvature to apply to the chair back rest, I will appreciate if someone can explain how he got the expression :- angle= 90degress-ATN((A/2)/B)/B))*2,
What is and where does he get ATN ?
Also why multiply by 2(*) ?

I will appreciate your reply

Thank you

Femi

Re: Object making in AC 9,Page 66.

Anonymous — Mon, 16 Jun 2008 18:02:17 GMT

atn (x) is the GDL circular function arctangent which returns
an angle derived from the ratio of the opposite/the adjacent
sides of a right triangle. In the diagram this angle is half the
total included angle so the angle must be multiplied by two.
Peter Devlin