Question

10N

A tunnel has a semicircular cross-section
and a diameter of 10 m. If the roof of a bus
just touches the roof of the tunnel when
the bus is 2 m from one side, how high is
the bus?​

Answer 1

You should be able to solve this easily just by drawing the tunnel and the bus (you may use 1cm for 1m). Notice how the bottom of the tunnel, the side of the bus, and a radius of the tunnel form a right-angled triangle. All you need to do is to find the sides of the triangle.