Question

AC是路灯,为了测量它高度,小明采用如下方法∶把长1.6米的标杆立在地

Answer 1

BEF与BCA相似：

EF:AC = BF :AB

AC = AB*EF/BF (1) 这里EF = 1.6

AFE与ABD相似：

AF :AB = EF :DB = 1.6 :2

AF = AB - BF

(AB - BF)/AB = 1.6/2 = 0.8

1 - BF/AB = 0.8

BF/AB = 0.2

AB/BF = 1/0.2 = 5 (2)

(2)代入(1):AC = 1.6*5 = 8