How to find the missing length of an isosceles trapazoid

The video tutorial explains how to identify and analyze an isosceles trapezoid. It begins by identifying the figure based on its properties, such as congruent opposite sides and parallel sides. The tutorial then delves into the properties of an isosceles trapezoid, emphasizing the importance of congruent angles. The instructor guides students through solving for the measure of angle M using the concept of supplementary angles formed by a transversal intersecting parallel lines. The video concludes with a reminder to write down equations to avoid calculation errors.

If one angle measures 142 degrees, what is the measure of the other angle in the isosceles trapezoid?

Why is it important to write down the equation for finding the measure of an angle in a trapezoid?