Problem #$3$: Rigid body equilibrium in $2$D $(14$ points$)$

Beam $AB$ is supported at point $A$ by a hinge and at point $B$ by a roller. A distributed force acts on the beam as shown below and a force of $100$ N acts vertically downward at point $B.$

a$)$ Draw a free$-$body diagram and replace the distributed load by resultant force$($s$)$ and give the location of the resultant force$($s$).$

b$)$ Find the support reactions at points A and $B.$