This topic focuses on applying the Pythagorean theorem to solve for unknown side lengths in right triangles, using decimal values. Students practice manipulating equations to isolate and approximate the value of one side, labeled as 'a' or 'b', when the squared values of the other sides are given. These exercises help in reinforcing the concepts of roots and squares, precision in calculations, and handling algebraic expressions to solve real-world geometry problems. This forms part of a foundational unit on Pythagoras' theorem.