Problem $2(40$ points$).$ For the given frame, answer the questions using Moment$-$Area Method:

$($a$)[10$ points$]$ Draw the curvature diagram of the frame.

$($b$)[20$ points$]$ Moment$-$Area Method: Draw the elastic curve and show the geometric relations to find the

slope angle at point $C,{}_C,$ and the horizontal displacement at point $B,{}_B.$

$($c$)$ points$]$ Moment$-$Area Method: Calculate ${}_B.$