(a(i))[3]
For triangle $ABC$, $AC = 6.4\text{ cm}$, $BC = 9.5\text{ cm}$ and $\angle BAC = 79^{\circ}$. Calculate $\angle ABC$.
(a(ii))[3]
Calculate the area for triangle $ABC$.
(b(i))[3]
In pyramid $ABCD$, triangle $ABC$ is the horizontal base. If $BD = 9.8\text{ cm}$ and $CD = 8.2\text{ cm}$, with $\angle BAD = \angle CAD = 90^{\circ}$, calculate $\angle BDC$.
(b(ii))[2]
Calculate the elevation angle of $D$ as seen from $C$.