题目
如图,在离铁塔150m的A处,用测倾仪测得塔顶的仰角为30°12',测倾仪高AD为1.52m.求铁塔的高BC.(精确到0.1m)
(参考数据:sin30°12'≈0.5030,cos30°12'≈0.8643,tan30°12'≈0.5820)
答案:解:如图,过点A作BC的垂线,垂足为E. 单位:m 在△ABE中,tan30°12'= BEEA = BE150 ,. 则BE=150×tan30°12'≈87.30, ∴BC=BE+CE≈87.30+1.52≈88.8. 答:铁塔的高BC约为88.8m