Extracted text: 6-89. Determine the moment of inertia of the cross-sectional area of the beam about the y axis. 6-90. Determine y, which locates the centroidal axis x' for the cross-sectional area of the T-beam, and then find the moment of inertia about the x' axis. 150 mm 50 mm 150 mm 250 mm 25 mm 25 mm Probs. 6-89/90