In this activity, students must work together to guarantee each person can apply chord and tangent properties to solve these problems and justify how they know (MP1). I like using the Chord and Tangent Group Challenge to ensure that all students in a group are held accountable to the lesson’s learning objectives. When groups call me over to check in, I hold each member of the group accountable by shuffling their papers, selecting one paper at random, and quizzing that student before letting them advance to the next level.
At this point in the unit, I want to make sure students can use logical reasoning to write a proof involving properties of circles. I give this homework assignment so I can assess students' ability to incorporate precise academic and geometric vocabulary.