请按照如下方式生成视频,用于给初中生讲解题目:
1.读题目并绘制图象
2.以上传图片中标准解析为参考,来讲解题目
3.总结题目的考查知识点、难度、易错点---**Extraction Content:**
**Question Stem:**
如图,在等边△ABC中,D为AC中点,点P、Q分别为AB、AD上的点,BP = AQ = 4, QD = 2,在BD上有一点E,则PB+QE的最小值为
**Geometric Diagram Description:**
Type: Geometric figure (triangle with points and lines).
Main Elements:
- Triangle ABC.
- Point D is on side AC.
- Point P is on side AB.
- Point Q is on segment AD.
- Segment BD is drawn. Point E is on segment BD.
- Segments PQ, QE, and PE are drawn.
- A dashed line segment QQ' is shown, crossing BD, suggesting reflection. Point Q' is labeled. In the diagram within the solution, Q' is shown on segment CD.
- A dashed line segment PQ' is drawn, which intersects BD at point E.
- A dashed line segment Q'E is drawn.
- Vertices and points are labeled A, B, C, D, P, Q, E, and Q'.
**Other Relevant Text (Standard Solution/Analysis):**
标准解析
解:如图,∵△ABC是等边三角形,
∴BA=BC, ∠A = 60°
∵D为AC中点,
∴BD⊥AC,
作点Q关于BD的对称点Q′,连接PQ′交BD于E,连接QE,此时PE+QE的最小值最小PE+QE = PE+EQ′=PQ′.
∴BP = AQ = 4, QD = 2,
∴AD = DC = AQ + QD = 6, QD = DQ′ = 2
∴CQ′ = CD - DQ′ = 4 = BP,
∴AP = AQ′ = 8,
∴∠A = 60°,
∴△APQ′是等边三角形,
∴PQ′ = PA = 8,
∴PE + QE的最小值最小为8.