Circus Arithmagons

A circus is a company of performers that may include acrobats, clowns, trapeze acts and much more. A circus is fun to watch and is usually performed in a "big top" tent. Did you know that when a human cannonball is fired they travel at speeds of 60-70 miles per hour!

See if you can solve these four difficult arithmagons.

The aim of an arithmagon is to work out which numbers go in the empty circles. The numbers in the square boxes are made by adding together the numbers in the circles either side.