Israel 2013 Q1 - Star shape in a coin
Source: Israel National Olympiad 2013 Q1
August 8, 2019
geometryperimetercoins
Problem Statement
In the picture there are six coins, each with radius 1cm. Each coin is tangent to exactly two other coins next to it (as in the picture). Between the coins, there is an empty area whose boundary is a star-like shape. What is the perimeter of this shape?
https://i.imgur.com/aguQRVd.png