Fourth Grade Geometry 2 - Angles and Protractors Powerpoint Lesson is powerful when used as direct instruction in the classroom, online or individually. It teaches students all about angles: the definition, how to identify different types (obtuse, acute, right), how to measure them using a protractor and how to draw them. There are 22 effective teaching strategies used in this lesson base on research. For best results, students should have white boards and dry erase markers. Included i