Problem $2\mathrm{.}6($Related Topic: Distributed Loading, Equilibrium of a Rigid Body$)$:

Determine the reactions at point A and B $.($ A and B are points on the bar where smooth pin joint and roller are placed, respectively.$)$

PROOF OF THE PLACEMENT OF THE RESULTANT FORCE$($S$)$

IS A MUST. DO NOT DIRECTLY INDICATE THE CENTERS OF THE RECTANGLE AND TRIANGLE AS $1//2$ AND $2//3$ OF THE LENGTH, RESPECTIVELY. YOU MUST DEMONSTRATE HOW TO LOCATE THEM IN THAT MANNER, UTILIZING INTEGRATION FOR PROOF.