Why do this problem?
, the interactivity enables learners to experiment and
make their own conjectures about the locus. The proof requires only
simple geometrical reasoning involving circle theorems and arc
Learners might first experiment with the interactivity and
make a conjecture about the locus, then try to prove their
We know the small circle rolls around inside the big one. What can
we say about arc lengths?
Learners might draw their own interactive diagrams using Geogebra.
Ask about how far a bicycle goes forward when the wheels rotate
through exactly one revolution.
What about a revolution by a given angle?
What if the road was curved?
See the problem