Question

Moment of inertia of a triangle having base as b and height as h and axis is along the centroid and parallel the height.

(a) b*h^3/12

(b) h*b^3/36

(c) b*h^3/36

(d) b*h^3/6

This question was posed to me in a job interview.

I want to ask this question from Moments of Inertia of Areas in section Centres of Gravity, Moments of Inertia, Orthographic Reading and Conversion of Views of Engineering Drawing

Answer 1

Right option is (b) h*b^3/36

To explain I would say: The moment of inertia is sum of products of areas and squares of perpendicular distances from center of gravity.  And this gives the  moment of inertia of any planar section.