Show that for any triangle it is always possible to construct 3
touching circles with centres at the vertices. Is it possible to
construct touching circles centred at the vertices of any polygon?
Find the vertices of a pentagon given the midpoints of its sides.
Start with any number of counters in any number of piles. 2 players take it in turns to remove any number of counters from a single pile. The loser is the player who takes the last counter.
You probably need to consider the two people having alternate
segments of the pizza.
You could consider the areas of all the right angled isosceles
Alternatively, you could reduce the problem considerably by
removing a symmetrial portion of the pizza.