请帮我解答这道题,并且给我讲解一下这道题。---**Extraction Content:** **Question 17** **Question Stem:** 如图，在△ABC中，点 D，E 在边 BC 上，AE 为△ABC 的高，△ABD 的面积为 10，AE=5，CE=1。则 BD=___________ **Other Relevant Text:** Handwritten answer: 3 **Diagram Description:** * **Type:** Geometric figure (Triangle with internal lines and labels). * **Main Elements:** * Triangle ABC. Vertices are labeled A (top), B (bottom left), C (bottom right). * Base line BC with points D and E on it, located between B and C. The order of points on BC from left to right appears to be B, D, E, C based on the labels and relative positions. * Line segment AD. * Line segment AE. AE is drawn as the altitude from A to BC, indicated by a right angle symbol at E on BC. * Length labels: * AB = 10 * AE = 5 (labeled vertically from A to E) * DE = 3 (labeled on the segment DE on BC) * CE = 1 (labeled on the segment CE on BC) * Points A, B, C, D, E are labeled. * A right angle symbol is shown at point E on the line BC, indicating AE is perpendicular to BC.