$7\mathrm{.}4-7$ An element on the surface of a drive shaft is in pure shear and is subjected to stresses ${}_{xy}=2700,$ as shown in the figure. Using Mohr's circle, determine the following.

$($a$)$ The stresses acting on an element oriented at a counterclockwise angle $=52$ from the $x$ axis.

$($b$)$ The principal stresses.

Show all results on sketches of properly oriented elements.

Please do using Mohr's circle