1. In 2009, ............ was calculated to more than two trillion digits—in less than thirty hours.

pi

pi-dog

pious

Pi Day

2. ............ is a wild Asian dog, often roaming in packs in and around villages

Pi meson

Pi-dog

Pi

Pi day

3. ............ is a pion

Pi meson

Pi-dog

Pi day

Pi

4. ............ is the 16th letter of the Greek alphabet (II, π).

Pi meson

Pi

Pi dog

Pious

5. ............ are printing types mixed together indiscriminately.

Pies

Pi

Pie

none