38 mm x 155 mm
38 mm
    x
255 mm
Question 1 (20 marks):

A rectangular box beam is built from lumber with the dimensions 38 mm × 155 mm and 38 × 255 mm, as shown.

Find the moment of inertia of the beam, ICx, about the beam's horizontal centroidal axis Cx.

Solution:
 
ICx =
× 106 mm4