Find the measure of angle a in the triangle. Be sure to share all of your steps and use words like supplementary angles and Triangle Sum Theory in your explanation.

Type the correct answer in the box. consider the system of linear equations below. rewrite one of the two equations above in the form ax + by = c, where a, b, and c are constants, so that the sum of the new equation and the unchanged equation from the original system results in an equation in one variable.