Determine the missing variable using the sum of interior angles ex 1

The video tutorial demonstrates how to solve for the variable X in a polygon by using expressions for angles. It explains the sum of angles in a quadrilateral and how to set up and solve an equation to find the value of X. The process involves understanding the sum of interior angles, setting up an equation, and solving it step-by-step to find the missing variable.

How do you combine like terms when solving for the variable in the angle equations?

What is the value of X when solving the equation derived from the angles of the polygon?