I just had a question about the rules for explosive radius damage on a multi-dial figure.

If a multi-dail is hit with by a piece with explosive damage, do you draw the radius from the center dot of the multi-dial in all directions or does the radius only extend from the section that was hit?

i think it is from the center arc
i am only 95% sure, though

You always measure from the center dot. This, in effect, means that the explosive damage is almost negligible on dragons and completely non-existant for tanks.

You measure all around 3 inches, not just through the arc, all though the dragon, chariot, and tank are so huge, that it would not be able to hit anything.