=>> from Sines rule Sin A Sih B Sinc = a = k b C Sin A = ab Sin B = bk Sinc= 6+c-92 c+92 62 Cos A = CosB= 6056 = 209 2bc In equation ( +92 52 92462-2 + 2bc.ak + 2ca.bk Lab.ck => => 2 b + & - a + c+a - b +9+b-c 2abc k 2 c2 a+b a + b + c 2x 2 2abck a+b + c 4 x 1/2 9b sinc + b + c [ ab Sinc = a + b 29b ]