UVa 10209 Is This Integration ?

题目链接：http://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=41&page=show_problem&problem=1150

题意：求三块的面积

 1 #include <cstdio>
 2 #include <cmath>
 3 
 4 const double PI = acos( -1.0 );
 5 
 6 int main()
 7 {
 8     double a;
 9     while( scanf( "%lf", &a ) != EOF )
10     {
11         double z = ( 1 - sqrt( 3.0 ) / 4.0 - PI / 6.0 ) * a * a;
12         double y = ( 1 - PI / 4.0 ) * a * a - 2 * z;
13         double x = a * a - 4.0 * ( y + z );
14         printf( "%.3f %.3f %.3f\n", x, 4.0 * y, 4.0 * z );
15     }
16     return 0;
17 }