1 REM RAD IS RADIUS OF SPHERE
10 INPUT "RAD:";RAD
20 INPUT "FI:";FI
30 FI = FI*.0174532
40 REM FI IS NOW IN RADIANS
50 FOR Z = -10 TO 10
60 N = Z
70 GOSUB 260
80 MZ = MA
90 BZ = BA
100 FOR R = (Z+1) TO 10
110 N = R 
120 GOSUB 260
130 MR = MA
140 BR = BA
150 AB = (BZ-BR)/(MR-MZ)
160 REM AB IS ABSISSA OF INTERSECTING RAYS
170 OD = MR*AB + BR
180 PRINT "Z:";Z, "R:";R
190 PRINT "MZ;"; MZ, "BZ:";BZ
200 PRINT "MR:";MR,"BR:";BR
210 PRINT "ABSISSA=";AB, "ORDINATE=";OD
220 PRINT
230 NEXT R
240 NEXT Z
250 STOP
260 REM THE FOLLOWING COMPUTES MA AND BA GIVEN  'N'
270 X = RAD - (((RAD^2) - (N^2))^.5)
280 MO = -N/(((RAD^2)-(N^2))^.5)
290 TH = ATN(MO)
300 IF N > 0 THEN 360
310 IF TH < = FI THEN 340
320 KA = TH + ABS(TH - FI)
330 GOTO 370
340 KA = TH - ABS(TH - FI)
350 GOTO 370
360 KA = 2*TH - FI
370 MA = TAN (KA)
380 BA = N - MA*X
390 RETURN