问题:在2002年世界杯亚洲区十强赛中,中国国家足球队主场,即沈阳市五里河体育场的上空有一个半径为3米的大气球.在体育场外的A处有一球迷仰望气球中心点B,其仰角∠BAC=30°时,测得气球的视角为β=∠MAN=1°(若当正角θ很小时可取sinθ≈θ).该球迷运用其在中学阶段所学的数学知 Question: In the 2002 World Cup Asian Top 10, there was a large balloon with a radius of 3 meters above the home stadium of the Chinese national football team, namely the Wulihe Stadium in Shenyang. At the A outside the stadium, a fan looked up at the center of the balloon. B, when the elevation angle ∠BAC=30°, the measured angle of the balloon is β=∠MAN=1° (when the positive angle θ is very small, sinθ≈θ is desirable). The fan uses the mathematics learned in the middle school stage.