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Tunnel Vision

Age 14 to 16 Short Challenge Level:

A tunnel is cut through a hillside, with a semi-circular cross-section.


A truck of height 6 m can just drive with its nearside wheels 2 m from the point where the curved roof meets the horizontal road surface.

How wide is the tunnel?

This problem is taken from 1000 Problems to Enjoy
You can find more short problems, arranged by curriculum topic, in our short problems collection.