program twolines

C**********************************************************************
C  Read in the coefficients of A, B, C and D, E, F for two lines where:
C	Ax + By = C
C	Dx + Ey = F
C  Determine if the lines intersect, are parallel or perpendicular
C**********************************************************************

      real coeffA, coeffB, coeffC
      real coeffD, coeffE, coeffF
      real slope1, slope2

      print *, 'Enter coefficients for line 1: '
      read *, coeffA, coeffB, coeffC

      print *, 'Enter coefficients for line 2: '
      read *, coeffD, coeffE, coeffF

C-----SLOPE OF LINE IS (-A/B)
      slope1 = coeffA / coeffB * (-1.0)
      slope2 = coeffD / coeffE * (-1.0)

      print *, 'Slope of line 1 is ', slope1
      print *, 'Slope of line 2 is ', slope2

      if (slope1 .eq. slope2) then
          print *, 'The two lines are parallel.'
      else
          print *, 'The two lines intersect.'
      end if

      if ((slope1 * slope2) .eq. (-1.0)) then
          print *, 'The lines are perpendicular to each other.'
      end if

      stop
      end