Copyright © University of Cambridge. All rights reserved.

The diagram shows three touching circles each of radius $5$cm and a line which touches two of them.

Find the total length of the perimeter of the two shaded shapes.

Leave $\pi$ in your answer.

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.**View the archive of all weekly problems grouped by curriculum topic*