What's the formula of the moment of inertia of a triangle?

Question

and a circle too..

Answer 1

triangle: (b * (h ^ 3)) / 36

circle: (3.1416 * (r ^ 4)) / 4

in case you need one for the rectangle: bh^3/12..

and for the record, what's wrong with you anyway, billruss..? this is basic dynamics! howd you become a top contributor anyway?

Answer 2

triangles and circles are abstract mathematical constructs. They have no mass, and no moment of inertial.

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Answer 3

For the triangle;

I =( bh^3)/36

Where;

I = moment of inertiain units ^4

b = base in unit of length

h = height in the same length unit as the base

For the circle;

I = pi( d^4)/64

Where d = diameter of the circle