讲解下这道题 ---**Problem Description:** 如图，在△ABC中，BC = 2，tan B = $\frac{1}{2}$，点D是BC延长线上一点，tan∠ACD = $\frac{3}{4}$. **Diagram Description:** * Type: Geometric figure (triangle and line segment). * Main Elements: * Points: A, B, C, D. * Lines: Straight lines forming triangle ABC (segments AB, BC, AC). Straight line extending from BC through C to D (line segment BD). Point C lies between B and D. * Shapes: Triangle ABC. * Relative Position and Direction: Points B, C, D are collinear and lie on a horizontal line from left to right in the order B, C, D. Point A is located above the line BD, forming a triangle ABC with base BC. The line segment AC is drawn. **Sub-question (1):** 简答题 求点A到BD的距离； **Sub-question (2):** 简答题 求sin A的值.