Q$3.$ From the $2$D stress element, use the Mohr's circle method and determine

$($a$)$ Major and minor principal stresses. $(10$p$)$

$($b$)$ What is the angle to rotate in order to get the normal stress as principal stress? $(10$p$)$

$($c$)$ What is the magnitude of the maximum shear stress? $(10$p$)$