The equation of directrix and latusrectum of a parabola are $3\mathrm{x}-4\mathrm{y}+27=0$ and $3\mathrm{x}-4\mathrm{y}+2=0$ then length of latusrectum is 

Directrix $3\mathrm{x}-4\mathrm{y}+27=0$

Latus Spectrum $3\mathrm{x}-4\mathrm{y}+2=0$

Directrix and latusrectum are parallel and  distance between them  is 2a

$$\begin{gathered} 2\mathrm{a}=\frac{\left|27-2\right|}{\sqrt{9+16}} \\ \Rightarrow 2\mathrm{a}=5 \end{gathered}$$

Length of latusrectum $=4\mathrm{a}=10$