In Fig. 29-39, two circular arcs have radii $a=13.5 \mathrm{~cm}$ and $b=10.7 \mathrm{~cm},$ subtend angle $\theta=74.0^{\circ}$ carry current $i=0.411 \mathrm{~A},$ and share the same center of curvature $P$. What are the (a) magnitude and (b) direction (into or out of the page) of the net magnetic field at $P ?$