A rectangular plate is subjected to the loading shown in the figure. The allowable normal stress for the material is ${}_{\text{a}\text{l}\text{l}}=206\frac{N}{m}{m}^2.$ Assuming uniform stress distribution, determine the thickness $($t$)$ of the plate, according to:

a$)$ Maximum normal stress criterion.

b$)$ Maximum shearing stress criterion.

c$)$ Maximum distortion energy criterion.

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