Construct a regular hexagon of side $5.5 \; cm$, with an inscribed circle. Measure the radius of the incircle.
Construct a regular hexagon $ABCDEF$ of side $5.5 \; cm$.
Construct the angle bisectors of the interior angles $A$ and $B$. The angle bisectors meet at point $I$.
From point $I$, draw $IP$ perpendicular to $AP$.
With $I$ as center and $IP$ as radius, draw a circle which touches all the sides of the regular hexagon.
Radius of the incircle $= 4.7 \; cm$