Ryan has a corn field which is shaped as showns below in the figure. If $\angle{DAB}=90^{\circ}$ Find the area of the field.

Question

$\begin{array}{1 1} (a)\; \text{300 sq. ft} \\ (b)\; \text{306 sq. ft} \\(c)\;\text{308 sq. ft } \\ (d)\; \text{310 sq. ft} \end{array}$