1. The problem states a geometric pattern where a figure's number of sides increases linearly, starting with a triangle (3 sides) and adding 2 sides for each consecutive figure. 2. The general formula provided for the number of sides for figure $n$ is $T_n = 2n + 1$. 3. We need to find the number of sides for Figure 15, so substitute $n = 15$ into the formula: $$T_{15} = 2 \times 15 + 1$$ 4. Calculate the expression: $$T_{15} = 30 + 1 = 31$$ 5. Therefore, Figure 15 has 31 sides. The correct answer is B. 31.