You may also like

problem icon


A floor is covered by a tessellation of equilateral triangles, each having three equal arcs inside it. What proportion of the area of the tessellation is shaded?

problem icon

Getting an Angle

How can you make an angle of 60 degrees by folding a sheet of paper twice?

problem icon

Arclets Explained

This article gives an wonderful insight into students working on the Arclets problem that first appeared in the Sept 2002 edition of the NRICH website.

Stellar Angles

Stage: 3 Short Challenge Level: Challenge Level:1

What is the value of $x$ in the diagram?

If you liked this problem, here is an NRICH task which challenges you to use similar mathematical ideas.
This problem is taken from the UKMT Mathematical Challenges.
You can find more short problems, arranged by curriculum topic, in our short problems collection.