It is not reasonable. The LCD can be less than the denominators if the fractions are not in simplest form but the LCD can be equal to one of the fractions even if they are in simplest form, for example: 3/4 and 1/2
The length of the field will be calculated as: P=2(L+W) P=376 W=89 thus substituting the values in the equation we get; 376=2(L+89) 376/2=(L+89) solving for L; 188=L+89 L=188-89 L=99 yards therefore the length is 99 yards