EngageNY
Unknown Angle Proofs—Writing Proofs
What do Sherlock Holmes and geometry have in common? Why, it is a matter of deductive reasoning as the class learns how to justify each step of a problem. Pupils then present a known fact to ensure that their decision is correct.
Curated OER
What is my Angle? App
Learners estimate angle measures in this this estimating angle measures lesson. They use an application on their graphing calculator that shows various settings involving angles and then they estimate the angle measure of a clock's...
Curated OER
Positive and Negative Angles and Arcs
To better understand that the intersection point of two lines lies inside a circle, learners use their keen measurement skills. They discuss arcs, rays, tangent lines, and reflex angles. Then, they put their skills to work as they...
Curated OER
Angle Action 1,2 and 3
Students investigate angles through construction. In this geometry instructional activity, students use a protractor to identify the measurement of an angle. They identify angles cut by a transversal and two parallel lines.
Curated OER
Why Doesn't SSA Work?
Students investigate the relationship between angles and their sides. In this geometry activity, students prove why SSA does not work as a true angle side relationship theorem.