A single machine connected to infinite bus has H $=3\mathrm{.}0$ pu$,$ and Xd$=0\mathrm{.}25$ pu and line reactance $=0\mathrm{.}1$ pu$.$ Initially the bus voltage $($generator bus$)$ is $1\mathrm{.}4$ pu and the generator was delivering a power of $75$ MW$.$ At t $=0$ s$,$ a $3$ phase short circuit occurred at the generator bus which is cleared at t $=0\mathrm{.}15$ s$.$ Find the variation of rotor angle with respect to time up to t $=0\mathrm{.}40$ second, taking time step of $0\mathrm{.}05$ second. Given that, base MVA is $100$ and infinite bus voltage is $1\mathrm{.}0$ pu$.$ Use Euler$$s method.