Techniques and results on approximation algorithms for packing circles

This survey provides an introductory guide to some techniques used in the design of approximation algorithms for circle packing problems. We address three such packing problems, in which the circles may have different sizes. They differ on the type of the recipient. We consider the classical bin packing and strip packing, and a variant called knapsack packing. Our aim is to discuss some techniques and basic algorithms to motivate the reader to investigate these and other related problems. We also present the ideas used on more elaborated algorithms, without going into details, and mention known results on these problems.