MathDB
A Lot of Curves

Source: 2002 National High School Mathematics League, Exam One, Problem 14

March 16, 2020
geometry

Problem Statement

There is a family of curves: P0,P1,P2,P_0,P_1,P_2,\cdots. P0P_0 is a regular triangle, whose area is 11. For all kZ+k\in\mathbb{Z}_+, PkP_k is defined in this way: trisect all sides of Pk1P_{k-1}, and draw outward a regular triangle with side of the segment in the middle, then cut off the segment in the middle. SnS_n is the area of PnP_n. (a) Find SnS_n. (b) Find limnSn\lim_{n\to\infty}S_n.