Students calculate the measures of arcs formed by tangents to circles by writing an equation to find that measure in this matching card activity. One half of the 20 pairs of matching cards has a diagram of the circle/ tangent arc and the other half has the measures of those angles. Students work individually, in pairs or small groups to match the cards.
This may be used as a challenge activity for students who have mastered finding tangent angle measures or as an early finisher activity. I find students LOVE doing the challenge problems. It is also a great refresher for students to practice writing and solving equations.
You can also use the activity as a warm up, competition, ticket in the door or out the door or in one of the other activities described in my free resource.