Problem: Circle I is circumscribed about a given square and circle II is inscribed in the given square. If r is the ratio of the area of circle I to that of circle II, then r equals:
Answer Choices:
A. 2β
B. 2
C. 3β
D. 22β
E. 23β
Solution:
Let s be the length of a side of the square. The radius of circle I is 21βs2β and its area K1β=21βΟs2. The radius of circle II is 21βs and its area K2β=41βΟs2.β΄r=K2βK1ββ=2