Anyone know how to answer this question

The circumference of a circle is 5 pi cm. what is the area of the circle?

Question part points submissions used suppose that 100 lottery tickets are given out in sequence to the first 100 guests to arrive at a party. of these 100 tickets, only 12 are winning tickets. the generalized pigeonhole principle guarantees that there must be a streak of at least l losing tickets in a row. find l.

Write two subtraction equations that are equivalent to 5 + 12 = 17.