Agent J

OJ: lightoj
problem no: 1331
 Step: 01)
     Find the area of the ABC triangle:(use the formula down below)
     s = (a + b + c) / 2;
    area of ABC = sqrt(s * (s - a) * (s - b) * (s - c)); Here, c = R1 + R2,  a =  R2 + R3, b = R3 + R1;
  Step: 02)
    Find the arg area of APR, BPQ, CQR.(use the formula down below)
    eg: for the APR case:
    arg area of APR = (<BAC * PI * R1*R1) / 360; Here angle is in rad unit 
   One more thing, you need to fin the angle as well[ cos a = (B*B + C*C - A*A) / (2*B*C) ];

    So, the final answer is...............
     area of PQR = area of ABC triangle - arg area of (APR + BPQ + CRQ)
     

__MD. SAMIUL ISLAM