For the flanged beam section shown in Figure $1$ with $f_c^{\text{'}}=35$MPa,$f_y=400$MPa, it is required to:

a$)$ Calculate the moment resistance $(M_r)$ given the reinforcement steel area $(As)$ shown in Figure $1.$

b$)$ Calculate the required A for the same concrete section dimensions, if $M_f=1000kN.$m$.$

c$)$ Draw the cross$-$section designed in $($b$)$ above, showing the details of the reinforcement according to the standards, assuming $M-{10}_{?}$ stirrups of two branches are used.