circle degrees

hi
got a circle, looking to find how to project a line with known
radius from the circle center to the perimeter at an angle of 60degs?
(although, the book I'm reading from is showing that the line of 60degs
is 120degs from point '0' as far as I can see it...... I know it all ends
up
in the same place, but I dont know two things:::;
1)why my book is showing an angle of 60degs when in fact its 120degs
from zero
2)how the heck I tell a/cad to draw a line from center of circle to a point
'x' amount of degrees for a radius length.

searched 'help', but got nowhere. ( too much other info offered, rather
than sticking to an elemetary question.)

 

type "L" <enter> osnap to center , type "@ (radius length)" <60 or 120
IOW if your circle is 100 units diameter
you'd type: L <enter> pick start point, then @50<60

 

Angle zero is at 3 o'clock, and is measured counter-clockwise as a default
in AutoCAD. Why? Think Descartes.
Longshot nailed the other question.

 

Like Michael said....... 'You nailed it'.
(boy, wish you were in front of my book right now
for my next problem, but I'll try and solve it myself first)
Thanks.....
Trying....

 

I just realised something, and this is a few minutes after I sent my
reply to Longshot.
You are right Michael, 0degs IS measured from 3'oclock, and this in
fact puts my 'book' in the Wrong.
It is telling me to draw a line from the centre of my circle at 60degs for
the length of the radius, BUT, it is showing me that the line should end
up at 120degs.........
Thanks, (makes me feel like writing to the author, but after thinking about
it, due to the authors mistake, my own inquiries taught me more)
Thanks Michael.
Trying.......

 

Keep going.