You may also like

problem icon

Efficient Packing

How efficiently can you pack together disks?

problem icon

Perfect Eclipse

Use trigonometry to determine whether solar eclipses on earth can be perfect.

problem icon

Construct the Solar System

Make an accurate diagram of the solar system and explore the concept of a grand conjunction.

Far Horizon

Stage: 4 Challenge Level: Challenge Level:3 Challenge Level:3 Challenge Level:3

The observer's line of vision is along a tangent to the surface of the earth at the far point she can see on the horizon. Imagine a right angled triangle with the observer at one vertex, the far horizon point at another vertex and the centre of the earth at the third vertex.

You have enough information to find the angles in this triangle and hence the distance required.