230 



PRACTICAL MATHEMATICS 



Let KL be another axis drawn parallel to OX and at a distance 

 y l from it. 



ab s z 



Then I VT = - 4- ab y. 



Putting 2/j = -, this becomes the moment of inertia about the 



M 



b 2 



( \ 



side AB, and I AB = ab -I -h > 



Let KM be an axis drawn parallel to OY and at a distance 

 from it. 



Then 



ba 3 

 = + ab 



Putting a?! = -, this becomes the moment of inertia about the 



m 



side AD, and 



I = ab 



AD 



FIG. 61. 



The figure shows the rectangle placed in isometric projection, 

 OZ being the axis drawn through the centroid perpendicular to 

 the plane of the figure. 



