Vertical angles have a very special quality. They are always congruent to one another! Check out this tutorial to learn about and see how to identify vertical angles!
select tools, including real objects, manipulatives, paper and pencil, and technology as appropriate, and techniques, including mental math, estimation, and number sense as appropriate, to solve problems
Knowing about supplementary angles can be very useful in solving for missing angle measurements. This tutorial introduces you to supplementary angles and shows you how to use them to solve for a missing angle measurement. Take a look!