Consider the plane element shown $($The $45$Mpa is compressive stress, the $27$Mpa is tensile stress, and the $18$Mpa is shearing stress$)$:

Required:

$1)$ Max tensile stress on the element

$2)$ Max shearing stress on the element

$3)$ Normal stress on oblique face ab

$4)$ Shear stress on the oblique face ab