Code:
1 ' Draw Circle in Degrees (GWBASIC)
2 ' Public Domain
10 CLS:KEY OFF:SCREEN 2:FOR A=1 TO 360
20 GOSUB 1000
30 XPOS = 160*COS(COSDEG) : YPOS = 80*SIN(SINDEG)
40 LINE (320,100)-(320+XPOS,100+YPOS)
50 NEXT A&#58;WHILE INKEY$<>" "&#58;WEND&#58;SCREEN 0&#58;KEY 
   ON&#58;END
1000 PI=3.141592&#58;COSDEG=A*PI/180 &#58; SINDEG=A*PI/180 &#58; 
     RETURN

---- Notes ----

Okay, so we're drawing a circle in 640x200 screen mode &
this was about as round as I could get it in this resolution
&#40;if it was 640x400 I might of been able to do more with it
in terms of how big & round I could have got it, but this
will do! ;-&#41;

In this program, I've started up a loop & created a subroutine
&#40;line 1000&#41; which calculates the degrees of the Cosine & 
Sine, returns & calculates the SIN & COS of that &#40;which 
obviously gives it it a result in Degrees - even though it's 
still in radians - thanks to the conversion formula, the result
comes out very well! &#58;-&#41;

I've made this program a little bit friendlier &#40;to that of the other 
two I posted a little while ago&#41; - in that at the end of the 
drawning cycle, the program pauses - this is when you can 
press space & it will take the user back to text mode 80x25
&#40;well I hope no-one protests about the 80x25 screen mode,
some of you might be into the 80x50, but if you're using 
GWBASIC which supports 80x50 &#40;mine doesn't - it's so ol'
that it doesn't do EGA! ;-&#41; feel free to change the SCREEN 0
at the end to whatever gets you into 80x50 &#40;or 80x43&#41;.
Cheers,
CP/M User.