The Protractor Series is a collection of educational resources designed to help students learn about geometry, particularly the properties and uses of angles. It often includes lessons on how to measure angles using a protractor, a tool that allows for precise angle measurement in degrees. The series may also cover related concepts such as complementary and supplementary angles. In addition to angle measurement, the Protractor Series typically features interactive activities and exercises that engage students in practical applications of geometry. This hands-on approach helps reinforce understanding and encourages students to explore geometric relationships in real-world contexts.