{"trustable":true,"prependHtml":"\u003cscript\u003e window.katexOptions \u003d { disable: true }; \u003c/script\u003e\n\u003cscript type\u003d\"text/x-mathjax-config\"\u003e\n MathJax.Hub.Config({\n tex2jax: {\n inlineMath: [[\u0027$$$\u0027,\u0027$$$\u0027], [\u0027$\u0027,\u0027$\u0027]],\n displayMath: [[\u0027$$$$$$\u0027,\u0027$$$$$$\u0027], [\u0027$$\u0027,\u0027$$\u0027]]\n }\n });\n\u003c/script\u003e\n\u003cscript async src\u003d\"https://mathjax.codeforces.org/MathJax.js?config\u003dTeX-AMS-MML_HTMLorMML\" type\u003d\"text/javascript\"\u003e\u003c/script\u003e","sections":[{"title":"","value":{"format":"HTML","content":"\u003cdiv class\u003d\"panel_content\"\u003eWe have a special convex that all points have the same distance to origin point.\u003cbr\u003eAs you know we can get N segments after linking the origin point and the points on the convex. We can also get N angles between each pair of the neighbor segments.\u003cbr\u003eNow give you the data about the angle, please calculate the area of the convex\u003cbr\u003e\u003c/div\u003e"}},{"title":"Input","value":{"format":"HTML","content":"There are multiple test cases.\u003cbr\u003eThe first line contains two integer N and D indicating the number of the points and their distance to origin. (3 \u0026lt;\u003d N \u0026lt;\u003d 10, 1 \u0026lt;\u003d D \u0026lt;\u003d 10)\u003cbr\u003eThe next lines contain N integers indicating the angles. The sum of the N numbers is always 360.\u003cbr\u003e"}},{"title":"Output","value":{"format":"HTML","content":"For each test case output one float numbers indicating the area of the convex. The printed values should have 3 digits after the decimal point.\u003cbr\u003e"}},{"title":"Sample","value":{"format":"HTML","content":"\u003ctable class\u003d\u0027vjudge_sample\u0027\u003e\n\u003cthead\u003e\n \u003ctr\u003e\n \u003cth\u003eInput\u003c/th\u003e\n \u003cth\u003eOutput\u003c/th\u003e\n \u003c/tr\u003e\n\u003c/thead\u003e\n\u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd\u003e\u003cpre\u003e4 1\r\n90 90 90 90\r\n6 1\r\n60 60 60 60 60 60\r\n\u003c/pre\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cpre\u003e2.000\r\n2.598\r\n\u003c/pre\u003e\u003c/td\u003e\n \u003c/tr\u003e\n\u003c/tbody\u003e\n\u003c/table\u003e\n"}}]}