[填空题]
The diagram below shows quadr+ t+o4 zd/n, hoy fyxr6i(sny+ilateral ABCD71 se r ebt75qdu tu8quj0( aia9q;w:w with side lengths of AD = 12 m, DC = 7 9u7 7i80:ed5qtaqt1sbq wr a;wueuj(m and BC = 5 m. Angle $\mathrm{B}\hat{\mathrm{A}}\mathrm{D}=50^{\circ}$ and angle $\mathrm{B}\hat{\mathrm{C}}\mathrm{D}=100^{\circ}$.
A new line is drawn from B to D direct.
1.Calculate the length of this new line, BD. m
2.Calculate the size of angle $\mathrm{A}\hat{\mathrm{B}}\mathrm{D}$. $^{\circ}$
