Find the maximum force in the connecting rod AB $($as a function of P$)$ needed for equilibrium. Lyles School of Civil Engineering $-$ Purdue University

Problem $1$

The piston in the mechanism shown is attached to a connecting rod $AB$ of length $L=13$ inches and to a crank arm $BC$ of length $R=5$ inches. The piston slides without friction in a cylinder and is subjected to a force $P$ of magnitude $P$ which is resisted by the moment $M$ on the crank arm as shown. The rodAB and arm $BC$ are pin$-$connected at both ends.

Find the maximum force in the connecting rod $AB($as a function of $P)$ needed for equilibrium. I dont have more info