For the state of plane stress shown in Fig. (a), determine the maximum in-plane shear stress and the absolute maximum shear stress.
Since the maximum in-plane shear stress equals the radius of the circle, which is also can be solved using the average formula of shear stress, I just used the mentioned formula. To get the absolute maximum shear stress, I used the given stress at x and the shear stress at y is zero at the absolute maximum shear stress, the answer for part B is 25 ksi.