Two Quadrances and a Spread

Consider a trilateral where two of the quadrances(square of the distance) are 16 and 25. The spread that separates these two quadrances is $\frac{24}{25}$ .

What is the quadrance of the third side?

You should use the Cross law: $(Q_1+Q_2-Q_3)^2 = 4Q_1Q_2(1-s_3)$

Where $Q_1=16, Q_2=25, s_3= \frac{24}{25}$