Two cables $($ AB and AC $)$ act on a hook at point A as shown in Figure $2\mathrm{.}3.$ Figure $2\mathrm{.}3$

a$)$ Determine the position vectors for the internal forces labeled $F_B$ and $F_C($Marks $2)$

b$)$ Express forces $F_B$ and $F_C$ in Cartesian vector form. $($Marks $2)$

c$)$ Determine the resultant force $R$ in Cartesian vector form and then determine its magnitude and

direction angles. $($Marks $3)$

d$)$ Determine the angle at A formed by cables AB and AC $.($Marks $2)$