Assume missing data and state clearly.

A rectangular slab $4m5m$ has fixed edges all over the supports. If the slab is isotropically reinforced with equal positive and negative reinforcement, shom that the ultimate moment capacity of the slab is

$M=\frac{w{L}_x^{2}ta{n}^2}{48}$

where $M=$ ultimate moment capacity of slab per unit length

$L_x=$ short span

$=$ Angle made by yield line with short span.

Also design the slab for working live load of $5k\frac{N}{m^2}$ using yield line properties. Use M$25$ and Fe $550$D materials.