对下题进行讲解的视频 如图，在▲ABC中，AB=AC, AC,AB 边上的高分别为BD，CE，且相交于点 O. 求证：▲ABC是等腰三角形.---Chart/Diagram Description: * **Type:** Geometric figure, specifically a triangle with intersecting line segments inside. * **Main Elements:** * **Points:** Points A, B, C, D, E, and O are labeled. * **Lines/Segments:** * A triangle ABC is formed by segments AB, BC, and AC. * Segment BD connects vertex B to a point D on side AC. * Segment CE connects vertex C to a point E on side AB. * Segments BD and CE intersect at point O, which is located inside the triangle. * **Labels:** Points are labeled A, B, C, D, E, and O. Point D is on segment AC. Point E is on segment AB. Point O is the intersection of segments BD and CE.