$3\mathrm{.}2$ Design the braced column $(350450mm)$ of the second floor as shown in Fig. $3b.$ Assume

that the minimum cover to the $10$ links is $20mm$ and $32$ longitudinal reinforcement is used.

The materials strengths are $f_{cu}=40\frac{N}{m}{m}^2$ and $f_y=500\frac{N}{m}{m}^2.$ The axial force in the column

$N=1500kN$ and the moments at top and bottom ends of the second floor column are as follows:

Top: $,M_{Ix}=200kNm$;$M_{ly}=120kNm$; Bottom: $M_{2x}=150kNm$;$M_{2y}=80kNm$

$(1)$ Determine if the column is short or slender.

$(5$ marks$)$

$(2)$ Design symmetrical reinforcement for the column section.

$(8$ marks$)$

$($unit: mm$)$

Fig$\mathrm{.}3$b Elevation view

I want to how to estimate or know the value of lex and ley