Question

A 20 cm radius pizza is cut into 8 equal slices. If a person wants 30cm of crust, how many slices should they take?

(answer is 2 but am unsure as how to get it)

Answer 1

since the whole circumference is 40π cm, each slice has 1/8 of that, or 5π ≈ 15 cm
30cm is thus about 2 slices