A right triangle has a hypotenuse of 13 units and one leg of 5 units. What is the length of the other leg?

1. Apply the Pythagorean Theorem: a squared plus b squared equals c squared. 2. Substitute the known values: 5 squared plus b squared equals 13 squared. 3. Simplify: 25 plus b squared equals 169. 4. Subtract 25 from both sides: b squared equals 144. 5. Take the square root of both sides: b equals 12. 6. Subtracting the leg from the hypotenuse directly, 13 minus 5, gives 8, which skips squaring and is not how the theorem works. 7. Adding the leg and the hypotenuse, 5 plus 13, gives 18, which is not a step the theorem calls for at all. 8. Reporting 169, the value of the hypotenuse squared before the leg is subtracted, mistakes an intermediate result for the final answer. _Source: OpenStax Prealgebra (CC BY 4.0), Ch 9 "Math Models and Geometry", section 9.3 Use Properties of Angles, Triangles, and the Pythagorean Theorem_