The moment of inertia of a disc of mass $M$ and radius $R$ about a tangent to its rim in its plane is

The moment of inertia of a triangular plate $ABC$ of mass $M$ and side $BC = a,$ about an axis passing through $A$ and perpendicular to the plane of the plate is :-

Seven identical coins are rigidly arranged on a flat table in the pattern shown below,so that each coin touches its neighbours. Each coin is a thin disc of mass $m$ and radius $r$. Note that the moment of inertia of an individual coin about an axis passing through its centre and perpendicular to the plane of the coin is $\frac{m r^2}{2}$. The moment of inertia of the system of seven coins about an axis that passes through the point $P$ (the centre of the coin positioned directly to the right of the central coin) and perpendicular to the plane of the coins is ..........$m r^2$.

The moment of inertia of a uniform disc of mass $M$ and radius $R$ about an axis passing through its edge and perpendicular to the disc is ..........

$A$ solid sphere of mass $M$ and a disc of mass $M/2$ have the same radius $R$. The ratio of the moment of inertia of the disc about a tangent in its plane to the moment of inertia of the sphere about its tangent is:

What is the moment of inertia of a disc about one of its diameters?