This math topic focuses on solving problems related to identifying the measurement of crossing angles against a straight line. It is categorized under basic 2D polygon geometry problem-solving. The problems involve finding the value of angle X, where multiple choice answers are provided for students to select from. This topic is tailored to enhance skills in understanding geometric properties and angle measures within various setups on straight lines intersected by other line segments. Each question contains an illustrative diagram to aid in visualizing the problem setup and determining the correct angle measure.