This resource focuses on understanding circles in a Cartesian plane. It covers identifying the center and radius from the standard equation of a circle, graphing circles based on their equations, and writing the standard equation when given a center and radius. The document includes worked examples with step-by-step instructions and practice problems for students to apply their knowledge. Sections are dedicated to graphing circles and translating graphical information into equations, ensuring comprehensive coverage of the topic. Additionally, there are self-explanation prompts to enhance understanding of how the signs in the equation affect the coordinates of the center. Finally, it offers challenging extension problems to push students' skills further.