This text for advanced undergraduates and graduate students examines problems concerning convex sets in real Euclidean spaces of two or three dimensions. It illustrates the different ways in which convexity can enter into the formulation as the solution to different problems in these spaces. Problems in Euclidean Space features four chapters that develop an increasingly dominant influence of convexity. In the first chapter, convexity plays a minor role; the second chapter considers problems originally stated in a wider context that can be reduced to problems concerning convex sets. In the third chapter, the problems are defined strictly for convex sets and not for more general sets, and the final chapter discusses properties of subclasses of the class of convex sets.