View Compilation Error

0_0_8566186_2706.cpp: In function `double Area(int, int, int, int, int, int)':
0_0_8566186_2706.cpp:36: error: `abs' undeclared (first use this function)
0_0_8566186_2706.cpp:36: error: (Each undeclared identifier is reported only once for each function it appears in.)