Help your geometry students understand the "why" behind the algorithms for special right triangles with this 7-page investigation and guided notes activity. Your students will use the Pythagorean Theorem and the properties of isosceles and equilateral triangles to discover how to solve for any side of a 45-45-90 and 30-60-90 triangle. Clear diagrams and step-by-step algebraic proofs allow students to develop the foundational understanding for working with these common right triangles, ensuring a smooth transition to the later study of trigonometry. Seven-page resource can be split up and taught over multiple class periods if needed, or use as independent study for test preparation later in the semester. Designed to address Common Core Math Standards HSA-CED.A.4, HSA-REI.A.1 and HSG-CO.C.10, this resource is perfect for students in Geometry or Algebra 2 but can be used for review or reteaching in higher-level math classes. Full key included. Error-free money-back guarantee!