讲解这道题目---Here is the complete and accurate extraction of content related to the question(s) from the image: --- **Question Stem (Problem 2):** 2. 结合图形，将“全等三角形对应边相等，对应角相等”用符号语言表述为。 (Translation: Combine with the diagram, express "corresponding sides of congruent triangles are equal, corresponding angles are equal" using symbolic language as ____.) **Relevant Information (Symbolic Representation for Congruent Triangles):** Based on the statement "corresponding sides of congruent triangles are equal, corresponding angles are equal", if we consider two congruent triangles, for example, △ABC and △DEF, the symbolic representation would be: If △ABC ≅ △DEF, then: * **Corresponding Sides:** * AB = DE * BC = EF * CA = FD * **Corresponding Angles:** * ∠A = ∠D * ∠B = ∠E * ∠C = ∠F --- **Chart/Diagram Description (Problem 2, 3, and 4):** **1. Diagram for Problem 2:** * **Type:** Geometric figure, consisting of two distinct triangles. * **Main Elements:** * **Shapes:** Two triangles. The first triangle has vertices A, B, C. The second triangle has vertices D, E, F. * **Lines:** Straight line segments form the sides of the triangles (e.g., AB, BC, CA for the first; DE, EF, FD for the second). * **Labels:** The diagram is explicitly labeled "(第 2 题)" which translates to "(Problem 2)". * **Relative Position:** The two triangles are placed side-by-side. Triangle ABC is positioned to the left of triangle DEF. There are some faint, possibly accidental, handwritten marks on the first triangle near vertices A and C. **2. Diagram for Problem 3:** * **Type:** Complex geometric figure, resembling a concave polygon or connected triangles. * **Main Elements:** * **Points:** Vertices labeled A, B, E, C, F, D. * **Lines:** Multiple straight line segments connect these points, forming a complex shape (e.g., AB, BE, EC, CF, FD, DA are visible segments). * **Annotations/Labels:** * An angle near vertex A is marked with 'b°'. * An angle near vertex C (specifically ∠BCE) is marked with '2y'. * Another angle near vertex C (specifically ∠ECF) is marked with '2a'. * There is a numerical label '24' positioned next to a short segment near B, possibly indicating a length or value, and a small perpendicular line mark is also present near C. * **Labels:** The diagram is explicitly labeled "(第 3 题)" which translates to "(Problem 3)". **3. Diagram for Problem 4:** * **Type:** Geometric figure, consisting of two overlapping triangles. * **Main Elements:** * **Shapes:** Two triangles. The first triangle has vertices A, B, C. The second triangle has vertices D, E, F. * **Lines:** Straight line segments form the sides of the triangles (e.g., AB, AC, BC for △ABC; DE, DF, EF for △DEF). * **Labels:** The diagram is explicitly labeled "(第 4 题)" which translates to "(Problem 4)". * **Relative Position:** The two triangles are overlapping. Their bases (BC and EF) appear to be collinear, forming a longer segment B-E-C-F. Vertex A is above BC, and vertex D is above EF. Vertex E of △DEF lies on the base BC of △ABC, and vertex C of △ABC lies on the base EF of △DEF.