Spirals

Taking a sip of his tea, Dr Zonga pondered on how to measure the length of the spiral on his tea-coaster.

The image on the right is a slightly easier spiral to work with. Assuming each square is 1cm in length, what is the circumference of the spiral?  

Think you've got the answer?

Check it here

 The solution was given LIVE on Instagram, 5pm (CET), 4th June 2021. 

Click here to watch