1. The problem asks about the location of sides labeled $a$ and $b$ in a right triangle. 2. In a right triangle, the sides are typically named as follows: the side opposite the right angle is the hypotenuse, and the other two sides are called legs. 3. The labels $a$ and $b$ usually represent the legs of the triangle, but which one is the base depends on the context or the figure's orientation. 4. The base is often chosen as one of the legs, either $a$ or $b$, depending on the problem or diagram. 5. There is no fixed rule that $a$ must be the base or $b$ must be the base; it depends on how the triangle is drawn or defined. 6. To summarize, $a$ and $b$ are the legs of the right triangle, and either can be the base depending on the situation.