This topic focuses on determining unknown angles in various polygon configurations, specifically within triangles and isosceles triangles. It is a beginner level part of a larger unit on solving problems involving 2D polygons. The problems require students to identify specific angle values using provided geometric figures and a list of multiple-choice options. Each question presents an image of a geometric shape with an angle marked as "X," where students must calculate the value of angle X from the given options. This helps improve students' understanding of basic geometric principles and angle calculations.