创建一个从哪个方面进行思考，并获得解题思路，然后完整的把题目做完，生成一个视频---**Title:**
最值题型盘点-168 反演
**Question Stem:**
如图, 正方形ABCD边长为4, 点G在AB上, ∠PCG=45°, S△PCG=4
**Question:**
求: DP的最小值?
**Diagram Description:**
* **Type:** Geometric figure.
* **Main Shape:** A square ABCD with vertices labeled A (bottom left), B (bottom right), C (top right), and D (top left).
* **Side Length:** The square has a side length of 4.
* **Point G:** Located on the side AB.
* **Point P:** Located within or on the boundaries of the square.
* **Lines:** Line segments connecting the vertices of the square (AD, AB, BC, CD). Line segments CG, CP, and DP are drawn.
* **Angle:** Angle ∠PCG is marked and labeled as 45°.
* **Annotation:** The text "阿古数学" is overlaid on the diagram, serving as a watermark.
* **Given Information:** The area of triangle △PCG is given as 4.
**Options:**
None provided in the image.
**Other Relevant Text:**
(None beyond the title, question stem, question, and diagram labels/annotations).