
The figure above shows the dimensions of a semicircular cross section of a one-way tunnel. The single traffic lane is 12 feet wide and is equidistant from the sides of the tunnel. If vehicles must clear the top of the tunnel by at least ½ foot when they are inside the traffic lane, what should be the limit on the height of vehicles that are allowed to use the tunnel?
5½ ft
7½ ft
8 ½ ft
9½ ft
10 ft
唉,但是谁规定通道一定要是矩形的?登录 或 注册 后可以参加讨论
其实就是勾股定理求一个h=8
8-0.5即可
不过不重要,如果直接完美接触,应该算出来的结果是8,那合理地缩一点,那便是B了。
所以,题目中的top,其实是指半圆的边上任意一点。