Moment of inertia of a semi circular wire of mass m?

If we are considering the semi circular wire of mass m to have a relatively small cross sectional radius, r compared to radius of the semi circular arc, R

And that we are considering the semi circular wire to lie in a xy plane. The mass moment of inertia taken about the z-axis (perpendicular to the plane) located at the cg position will be.

Izz=m*(R^2)*(PI-(4/PI))/PI

I did a check of this calculation with the way Catia calculated the same property. And the difference was found to be 0.03% When using the following geometry.

density=0.000001kgmm^3

Semi circular wire Radius R =60mm

cross sectional radius of wire = 1mm

results from Catia

V=592.176mm^3

m=0.000592176kg

Izz=1.268159kgmm^2

hand calculated results

V=592.176mm^3

m=0.000592176kg

Izz=1.267835kgmm^2

% difference [((1.268159)-(1.267835))/(1.267835)]*100=0.03%

Please carry out a check on the Izz calc. I determined it from 1st principles, so I may of made a mistake