(i)[2]
State the distances from $AB$ and from $BC$ to the centre of mass of the lamina.
(ii)[2]
The lamina is freely suspended at $B$ and settles in equilibrium. Find the angle between $AB$ and the horizontal.
(iii)[3]
A force of magnitude $12\,\text{N}$ acts along the edge $AC$ of the lamina in the direction from $A$ towards $C$. The lamina, still suspended at $B$, is now in equilibrium with $AB$ vertical. Calculate the weight of the lamina.