👉 Learn how to find the value of an unknown variable in the expressions representing the values of angles given the ...

👉 Learn how to define angle relationships. Knowledge of the relationships between angles can help in determining the value of a given angle. The various angle relationships include: vertical angles, ...

Angles that add together to make a straight line are called supplementary angles. If you know one supplementary angle you can subtract it from 180° to find a missing angle.