怎么解这道题？---```plain Problem 25. (Total score 14 points, where part (1) is 9 points, sub-part ① is 4 points, ② is 5 points, part (2) is 5 points) Question Stem: As shown in Figure 9, in parallelogram ABCD, points E, F are points on sides BC, CD respectively. (1) If E is the midpoint of BC; ① If AE = EF, prove: ∠BAE = ∠EFC; ② If CF = DF, connect BF intersecting AE at G, find the value of S△BEG : S△AEF; (2) As shown in Figure 10, if AB=3, AD=5, CF=1, ∠AEB = ∠AFE = ∠EFC, find the length of AF. Figure 9 Description: Type: Geometric figure (Parallelogram). Main Elements: - Parallelogram ABCD. Vertices A, B, C, D are labeled in counter-clockwise order. - Point E is on side BC. - Point F is on side CD. - Line segments connecting A to E, A to F, E to F, and B to F are drawn. - The figure is labeled "图9" (Figure 9) below it. Figure 10 Description: Type: Geometric figure (Parallelogram). Main Elements: - Parallelogram ABCD. Vertices A, B, C, D are labeled in counter-clockwise order. - Point E is on side BC. - Point F is on side CD. - Line segments connecting A to E, A to F, E to F, and B to F are drawn. - The figure is labeled "图10" (Figure 10) below it. - The relative positions of E and F appear different from Figure 9. E seems closer to B and F seems closer to D in this figure compared to Figure 9 (based on visual inspection and assuming Figure 9 corresponds to the conditions in part 1). Other Relevant Text: - "S△BEG" represents the area of triangle BEG. - "S△AEF" represents the area of triangle AEF. - Units for lengths (AB, AD, CF) are implied to be consistent but not explicitly stated. - Units for angles are implied to be degrees or radians but not explicitly stated. ```