PV_LAB1

!23456
      PROGRAM MAIN
      COMMON /TRDATA/ A, B, ALPH
      COMMON /SLAVE/ RMIN, CA, CB, PI
      PI = 3.14159265
      RMIN = -1.0
      CALL MENU
      PRINT*, '----------------------------'
    1 READ *, ICOMMAND
      SELECT CASE (ICOMMAND)
      CASE (1)
       CALL ENTERNEWTRAINGLE
      CASE (2)
       CALL CALCULATEAREA
      CASE (3)
       CALL FINDSMALLESTANG
      CASE (4)
       CALL FINDSMALLESTCOS
      CASE (5)
       GOTO 2
      CASE DEFAULT
       PRINT *, 'UNEXPECTED COMMAND'
      END SELECT
      PRINT*, '----------------------------'
      GOTO 1
    2 END


C     ***MENU***

      SUBROUTINE MENU
      PRINT *, '1) ENTER TRAINGLE'
      PRINT *, '2) CALCULATING THE AREA OF A TRAINGLE'
      PRINT *, '3) CALCULATION OF THE SMALLEST ANGLE IN DEGREES'
      PRINT *, '4) CALCULATION OF THE COSINE OF THE MINIMUM ANGLE'
      PRINT *, '5) END OF WORK'
      PRINT *, '6!) WRITE TRAINGLE'
      END



C     ***ENTER NEW TRAINGLE***

      SUBROUTINE ENTERNEWTRAINGLE
      COMMON /TRDATA/ A, B, ALPH
      COMMON /SLAVE/ RMIN, CA, CB, PI
    3 PRINT *, 'ENTER FOLLOWING DATA:'
      PRINT *, 'A='
      READ *, A
      PRINT *, 'B='
      READ *, B
      PRINT *, 'ALPH=(GRADUES)'
      READ *, ALPH
      A = ABS(A)
      B = ABS(B)
      ALPH = ALPH/180*PI
      IF(A.LT.B.AND.ALPH.GT.ASIN(A/B)) THEN
       PRINT *, 'A TRAINGLE WITH THE GIVEN PARAMETERS DOES NOT EXIST!'
       GO TO 3
      ENDIF
      END



C     ***CALCULATE TRAINGLE AREA***

      SUBROUTINE CALCULATEAREA
      COMMON /TRDATA/ A, B, ALPH
      COMMON /SLAVE/ RMIN, CA, CB, PI
      CA = B*COS(ALPH)+(SQRT(A**2-(B*SIN(ALPH))**2))
      CB = B*COS(ALPH)-(SQRT(A**2-(B*SIN(ALPH))**2))
      IF (A.LT.B) THEN
        IF((A**2).GT.(B*SIN(ALPH))**2) THEN
            PRINT*, 'TRAINGLE MAY HAS THESE AREAS: '
            PRINT*,0.5*B*CA*SIN(ALPH)
            PRINT*,0.5*B*CB*SIN(ALPH)
        ELSE IF((A**2).EQ.(B*SIN(ALPH))**2) THEN
            PRINT 4, 0.5*B**2*SIN(2*ALPH)
    4       FORMAT('TRAINGLE HAS AREA: ', F7.4)
        ENDIF
      ELSE
        GAMMA = PI - ALPH - ASIN(B/A * SIN(ALPH))
        PRINT 5, 0.5*A*B*SIN(GAMMA)
    5   FORMAT('TRAINGLE HAS AREA: ', F7.4)
      ENDIF
      END



C     ***FIND SMALLEST ANGLE***

      SUBROUTINE FINDSMALLESTANG
      COMMON /TRDATA/ A, B, ALPH
      COMMON /SLAVE/ RMIN, CA, CB, PI
      IF(A.LT.B) THEN
       RMIN = A
       IF(B.LT.RMIN) RMIN = B
       IF(CA.LT.RMIN) RMIN = CA
       CA = RMIN
       PRINT 6, ASIN(CA / A * SIN(ALPH))*180/PI
    6  FORMAT('SMALLEST ANGLE IS: ', F7.4)
       RMIN = A
       IF(B.LT.RMIN) RMIN = B
       IF(CB.LT.RMIN) RMIN = CB
       CB = RMIN
       PRINT 7, ASIN(CB / A * SIN(ALPH))*180/PI
    7  FORMAT('ALSO IT CAN BE: ', F7.4)
      ELSE IF(A.EQ.B) THEN
        C = 2*B*COS(ALPH)
        RMIN = A
        IF(B.LT.RMIN) RMIN = B
        IF(C.LT.RMIN) RMIN = C
        PRINT 8, ASIN(RMIN/A * SIN(ALPH))*180/PI
    8   FORMAT('SMALLEST ANGLE IS: ', F7.4)
      ELSE
        C = B/COS(ALPH)
        RMIN = A
        IF(B.LT.RMIN) RMIN = B
        IF(C.LT.RMIN) RMIN = C
        PRINT 9, ASIN(RMIN/A * SIN(ALPH))*180/PI
    9   FORMAT('SMALLEST ANGLE IS: ', F7.4)
      ENDIF
      END



C     ***FIND COSINE OF SMALLEST ANGLE***

      SUBROUTINE FINDSMALLESTCOS
      COMMON /TRDATA/ A, B, ALPH
      COMMON /SLAVE/ RMIN, CA, CB, PI
      IF(A.LT.B) THEN
        PRINT 10,COS(ASIN(CA/A*SIN(ALPH))),COS(ASIN(CB/A *SIN(ALPH)))
   10   FORMAT('COSINE OF THE SMALLEST ANGLE: ', F7.4, F7.4)
      ELSE
        PRINT 11, COS(ASIN(RMIN/A*SIN(ALPH)))
   11   FORMAT('COSINE OF THE SMALLEST ANGLE: ', F7.4)
      ENDIF
      END