C-PS/8 FOCAL, 1971
 1.01 C     FROM TRIANG IN 	PROGRAMMING LANGUAGES	 COPYRIGHT 1970
 1.02 C     BY DIGITAL EQUIPMENT CORP.  REWRITTEN BY JOHN HUISMAN
 1.03 C     OMSI SOFTWARE DEVELOPMENT GROUP
 1.04 C     LAST CHANGE: 8/19/71
 1.05 
 1.06 C     GIVEN THREE PIECES OF INFORMATION             /I A2
 1.07 C ABOUT THE TRIANGLE SHOWN AT THE RIGHT            / I
 1.08 C THIS PROGRAM WILL DETERMINE THE OTHER           /  I
 1.09 C THREE PIECES.  HOWEVER, YOU MUST HAVE       S3 /   I
 1.10 C THE INPUT IN THE RIGHT ORDER.  THERE-         /    I S1
 1.11 C FORE, WHEN ASKED "TYPE", RESPOND WITH        /AREA I
 1.12 C "ASA" TO INPUT ANGLE-SIDE-ANGLE DATA,       /      I
 1.13 C OR "SAS" FOR SIDE-ANGLE-SIDE INPUT OR   A1 /-------I A3
 1.14 C "SSS" IF YOU KNOW THE SIDE LENGTHS.            S2
 1.15 C ** THIS MUST BE A RIGHT TRIANGLE.
 1.16 C ** BECAUSE OF THE ARCTANGENT FUNCTION,
 1.17 C    LENGTHS MUST BE UNDER ONE MILLION UNITS.
 1.18 
 1.26 I (FITR(/6)-(/6)) 1.27,1.3,1.27
 1.27 T "YOU DO NOT HAVE ENOUGH FEATURES.  "
 1.28 T "RESTART FOCAL WITH FEATURE 2.";Q
 1.29 E
 1.30 A "TYPE: ",TY;S A3=3.14159/2;I (FABS(TY-0ASA)) ,2.1
 1.40 I (FABS(TY-0SAS)) ,3.1;I (FABS(TY-0SSS)) ,4.1
 1.50 T !"LIST GROUP 1 FOR INSTRUCTIONS.",!!;Q
 2.10 D 6;A "A1: ",A1,!"S2: ",S2,
 2.20 I (FABS(DS)) ,2.3;S A1=A1*3.14159/180;S A2=3.14159/2-A1
 2.30 S S3=S2/FCOS(A1);S S1=FSQT(S3*S3-S2*S2)
 2.40 T !!:10,"RADIANS",:26,"DEGREES",!
 2.50 T !,"A1:",:7,A1,:24,A1*57.2958
 2.55 T !,"A2:",:7,A2,:24,A2*57.2958
 2.60 T !,"A3:",:7,A3,:24,A3*57.2958
 2.65 T !!"S1:",S1
 2.70 T !"S2:",S2
 2.80 T !"S3:",S3
 2.90 T !!"AREA =",%4.02,S1*S2/2,!!;G 1.29
 3.10 A "S1: ",S1,!"S2: ",S2
 3.20 S S3=FSQT(S1*S1+S2*S2);S A1=FATN(S1/S2)
 3.30 S A2=A3-A1;G 2.4
 4.10 A !"S1: ",S1,!"S2: ",S2,!"S3: ",S3,!
 4.20 S A1=FATN(S1/S2);S A2=A3-A1;G 2.4
 6.10 A "ARE YOUR ANGLES IN DEGREES
 ",ANSWER
 6.20 I (-FABS(AN-0YES)) 6.3;S DSWITCH=1;R
 6.30 I (-FABS(AN-0NO)) 6.4;S DSWITCH=0;R
 6.40 T "YES OR NO.",!;G 6.1