Pre-Calculus

from math import pow, sqrt, cos, acos, radians, degrees

def SSS():
    try:
        a = input( "a = " )
        b = input( "b = " )
        c = input( "c = " )
    except:
        print( "Input must be numbers only.\n" )

        return

    try:
        A = degrees( acos( ( pow( b, 2 ) + pow( c, 2 ) - pow( a, 2 ) ) / ( 2 * b * c ) ) )
        B = degrees( acos( ( pow( a, 2 ) + pow( c, 2 ) - pow( b, 2 ) ) / ( 2 * a * c ) ) )
        C = degrees( acos( ( pow( a, 2 ) + pow( b, 2 ) - pow( c, 2 ) ) / ( 2 * a * b ) ) )

        degreeSymbol = unichr( 176 )

        print( "\nA = %.1f%s\nB = %.1f%s\nC = %.1f%s\n" % ( A, degreeSymbol, B, degreeSymbol, C, degreeSymbol ) )
    except Exception, e:
        print( "\n%s\nPlease check your input and try again.\n" % ( e ) )

def SAS():
    side = raw_input( "Side: " )

    if( side == "a" ):
        try:
            b = input( "b = " )
            c = input( "c = " )
            A = input( "A = " )
        except:
            print( "Input must be numbers only.\n" )

            return

        try:
            a = sqrt( pow( b, 2 ) + pow( c, 2 ) - ( 2 * b * c * cos( radians( A ) ) ) )

            print( "\na = %.1f\n" % ( a ) )
        except Exception, e:
            print( "\n%s\nPlease check your input and try again.\n" % ( e ) )
    elif( side == "b" ):
        try:
            a = input( "a = " )
            c = input( "c = " )
            B = input( "B = " )
        except:
            print( "Input must be numbers only.\n" )

            return

        try:
            b = sqrt( pow( a, 2 ) + pow( c, 2 ) - ( 2 * a * c * cos( radians( B ) ) ) )

            print( "\nb = %.1f\n" % ( b ) )
        except Exception, e:
            print( "\n%s\nPlease check your input and try again.\n" % ( e ) )
    elif( side == "c" ):
        try:
            a = input( "a = " )
            b = input( "b = " )
            C = input( "C = " )
        except:
            print( "Input must be numbers only.\n" )

            return

        try:
            c = sqrt( pow( a, 2 ) + pow( b, 2 ) - ( 2 * a * b * cos( radians( C ) ) ) )

            print( "\nc = %.1f\n" % ( c ) )
        except Exception, e:
            print( "\n%s\nPlease check your input and try again.\n" % ( e ) )
    else:
        print( "Invalid input.\n" )

def heronArea():
    try:
        a = input( "a = " )
        b = input( "b = " )
        c = input( "c = " )
    except:
        print( "Input must be numbers only.\n" )

        return

    try:
        s = ( a + b + c ) / 2.0

        area = sqrt( s * ( s - a ) * ( s - b ) * ( s - c ) )

        print( "\nArea = %.1f\n" % ( area ) )
    except Exception, e:
        print( "\n%s\nPlease check your input and try again.\n" % ( e ) )

def main():
    while( True ):
        try:
            selection = input( "Selection:\n1 = SSS\n2 = SAS\n3 = Heron's Area Formula\nAnything Else = Exit\n" )

            if( selection == 1 ):
                SSS()
            elif( selection == 2 ):
                SAS()
            elif( selection == 3 ):
                heronArea()
            else:
                break
        except:
            print( "\nExiting...\n" )

            break

if __name__ == '__main__':
    main()