QUESTION $2-$ Analysis of frame using the Portal Method $(10$ Marks$)$ You are designing a small shopping complex which will be subject to the horizontal wind loads as identified below in Figure $2.$

$($a$)$ Analyse the rigid frame of the building, calculating the shear forces in the columns and beams using the portal method $($an approximate method$)$; and

$($b$)$ calculate the bending moments in the frame; and

$($c$)$ Draw the bending moment diagram for the frame.