Ancient Greek geometry is a branch of mathematics that developed in ancient Greece, primarily from the 6th century BCE to the 3rd century BCE. It is best known for its systematic approach to understanding shapes, sizes, and the properties of space. Key figures like Euclid and Pythagoras made significant contributions, with Euclid's work, particularly the "Elements," laying the foundation for modern geometry. The Greeks used geometric principles for various practical applications, including land measurement and architecture. They explored concepts such as points, lines, angles, and circles, establishing theorems that are still taught today. Their work emphasized logical reasoning and proof, influencing mathematics for centuries.