This packet contains 2 activities with answer keys. The first one is a self-exploration of the angles of a triangle. Students should use protractors to measure all three angles in a triangle and come up with they think would be a good rule for the sum of angles in a triangle. The second activity gives them the rule for the sum of angles in a triangle, and asks students to tell what the measure of one angle is if given the other two. For the second activity, students should not use a protractor, but should be able to add/subtract to find the measure of the missing angle.