at entrance to calc_distance: a = 3 b = 4 c = -2.49704e+38 entering calc_square: a = 3 b = 99 leaving calc_square: a = 9 b = 99 entering calc_square: a = 4 b = 99 leaving calc_square: a = 16 b = 99 calc_distance: dist. from 3 to 4 is 5 at exit from calc_distance: a = 3 b = 4 c = 5 main program says 5 at entrance to calc_distance: a = 6 b = 8 c = 1.91204e-40 entering calc_square: a = 6 b = 99 leaving calc_square: a = 36 b = 99 entering calc_square: a = 8 b = 99 leaving calc_square: a = 64 b = 99 calc_distance: dist. from 6 to 8 is 10 at exit from calc_distance: a = 6 b = 8 c = 10 main program says 10