The curves with equations $ x^n + y^n = 1 $, $ n = 4, 6, 8 \cdots , $ are called fat circles. Graph the curves with $ n = 2, 4, 6, 8, $ and $ 10 $ to see why. Set up an integral for the length $ L_{2k} $ of the fat circle with $ n = 2k $. Without attempting to evaluate this integral, state the value of $ \lim_{k\to\infty} L_{2k} $.