2.11 .Using of law cosines : TAc 2= 600(b)2 +800-2(600)(800) cos 30 TAc2 =168613 TAc = 411 Using law of sines : sin ?/600 =sin 30 Sin ?/600 = 2.965 *10-6 sin ? = 0.0017 Using of law sines : sin?/600 = sin 30 /411 sin ?/600 =0.00121 sin?=0.7299 ?=46.9