用数学老师的思维进行解答，并且一定要通俗易懂，让孩子看了一下就明白。 注意一定要切合原题目及图形，不要有误差，制图精准一些。---**Question Stem:** BDEF是长方形, AD=6, FC=5, 求绿色面积? (Translation: BDEF is a rectangle, AD=6, FC=5, what is the green area?) **Chart/Diagram Description:** * **Type:** Geometric figure showing a large right-angled triangle ABC with a rectangle BDEF inscribed within it. * **Main Elements:** * **Points:** Labeled points A, B, C, D, E, F. Point B appears to be at the origin or a vertex of a right angle. * **Lines:** Straight lines forming triangles ABC, ADE, EFC, AEF, BDF, and the rectangle BDEF. * **Shapes:** * Triangle ABC: A large triangle, appears to be a right-angled triangle with the right angle at B. * Rectangle BDEF: A rectangle inscribed within triangle ABC, with vertices B, D, E, F. Side BD lies on AB, side BF lies on BC. * Triangle ADE: A triangle above the rectangle, with vertices A, D, E. * Triangle EFC: A triangle to the right of the rectangle, with vertices E, F, C. * Triangle AEF: A green-shaded triangle within triangle ABC, with vertices A, E, F. * Triangle BDE and Triangle BEF are implied by the rectangle. * Triangle BDF is implied by the rectangle. * Triangle BFE is implied by the rectangle. * Triangle BEF is a green-shaded triangle, formed by the diagonal BE of the rectangle and side BF. * **Labels and Annotations:** * Point labels: A, B, C, D, E, F at the vertices. * Length labels: "6" next to segment AD. "5" next to segment FC. A yellow line segment under FC might be an emphasis mark. * **Green Areas:** Two areas are shaded green: triangle AEF and triangle BEF. * **Relative Position:** Rectangle BDEF has vertices D on AB, F on BC, and E on AC. Point A is above D and B. Point C is to the right of F and B. D is on AB, F is on BC. E is connected to D, B, F, A, and C. * A white triangular play button icon is overlaid on the image, centered over the green area formed by rectangle BDEF and triangle AEF/BEF. This is likely a UI element from a video. It is not part of the geometric problem itself.