Product Description: This instant feedback, sum by tab activity covers corresponding, alternate exterior, alternate interior, same-side exterior, same-side interior, vertical angles, and linear pairs. There are 20 problems - all clean, multi-step equations. Students will need to either set two expressions equal to each other or sum two expressions and set equal to 180 degrees on most problems. In this Christmas edition, students will need to solve for the unknown variable and substitute the vari