如图，正方形ABCD中，E、F分别为AB、BC的中点，EC和DF相交于G，连接AG，求证：AG=AD。---**Chart/Diagram Description:** * **Type:** Geometric Figure. * **Main Elements:** * A rectangle ABCD is shown. The vertices are labeled A, B, C, D in counterclockwise order, starting from the top left. * Point E is on the side AB. * Point F is on the side BC. * Line segment AF is drawn. * Line segment CE is drawn. * Point G is the intersection of line segments AF and CE. * Point H is located outside the rectangle. * A dashed line segment AH is drawn, extending to the left from A. * A dashed line segment CH is drawn, passing through point E and extending to H. **Other Relevant Text:** * 公众号 帝源初中数学课