Q$3$ Application of design chart for column design

Using an appropriate design chart $($Figure $3),$ calculate the area of reinforcement required to

resist a design compressive force that varies in the range $440-600kN$ combined with a uniaxial

design moment in the range $110-145kNm.$ The characteristic strength $f_{yk}=500\frac{N}{m}{m}^2,f_{ck}=$

$35\frac{N}{m}{m}^2.$ The column is short and has the dimensions as Figure $4.$

Figure $3$ Interaction diagram for different percentages of reinforcement

Figure $4$ Dimension and material properties