$1)$ Three straight members $($ABC$,$ BD and DCE are connected by pins at B$,$ C and D$.$ The force Q with equal horizontal and vertical components $(20$ kN $)$ is applied at D$.$ A single shear connection is used to connect members BD and DCE at D$.$ The pin at D has a diameter of $12$ mm $.$ Member BD has a rectangular cross section with a width of $40$ mm and a thickness of $30$ mm $($out of plane thickness$).$ There is a pin support at A and a vertical roller at E$.$ Determine

a$.$ The maximum axial stress in BD$.$

b$.$ The maximum shearing stress in the pin at D$.$