Question

如图.一艘轮船按箭头所示方向行驶,C处有一灯塔,请你根据图中所标数据求∠ACB的大小.当轮船距离灯塔C最近时,∠ACB是

Answer 1

∠ABC=180°-70°=110°

∠ACB=180°-∠A-∠ABC

=180°-30°-110°

=40°

当轮船距离灯塔C最近时,即BC⊥AB

∴∠ABC=90°

∠ACB=180°-∠A-∠ABC

=180°-30°-90°

=60°