如图，路灯（
点）距地面8米，身高1.6米的小明从距路灯的底部（
点 ）20米的A点，沿OA所在的直线行走14米到B点时，身影的长度是变长了还是变短了？变长或变短了多少米？
如图，路灯（点）距地面8米，身高1.6米的小明从距路灯的底部（点 ）20米的A点，沿OA所在的直线行走14米到B点时，身影的长度是变长了还是变短了？变长或变短了多少米？
小明的身影变短了3.5米．
解析:
，
，
．··················································································· （2分）
，即
．
解得
．································································································ （4分）
同理，
可求得
····················································· （7分）
所以，小明的身影变短了3.5米．