This math topic focuses on understanding perpendicular slopes in the context of line equations. Students are required to identify line equations whose slopes are perpendicular to given slopes. The problems present a given slope, typically expressed as a fraction, and students choose the equation from multiple options that represents a line perpendicular to the initial slope. This set of problems enhances skills in converting and manipulating slopes, and applying the concept that the product of the slopes of perpendicular lines is -1.