1. 使用中文普通话语音解说，语速适中，语气亲切温和，适合8~9岁学生理解； 2. 以“提出问题 → 分析题意 → 解题步骤 → 数形结合演示 → 总结提升”的结构展开讲解； 3. 解题过程要完整，逐步讲解，关键步骤配有文字板书动画； 4. 使用图形辅助（如线段图、方格图、柱状图等）帮助孩子建立数形联系； 5. 结尾进行知识点总结，并鼓励孩子思考类似变式问题； 6. 视频长度建议2~3分钟，配合轻松背景音乐，画面风格适合小学生； 7. 如果有口算、估算、列式等过程，请逐步展开演示，避免跳步。同时延伸出快速计算公式，并学习，---The following content is extracted from the image: --- **Question Stem:** 2 数一数，下面的图形中各有多少个三角形？ (Translation: 2 Count, how many triangles are there in each of the following figures?) --- **Sub-question (1):** **Chart/Diagram Description:** * **Type:** Geometric figure (a rhombus or diamond shape). * **Main Elements:** * The outer boundary forms a rhombus. This rhombus has a top vertex, a bottom vertex, a left vertex, and a right vertex. * An internal horizontal line segment connects the left and right vertices of the rhombus. * There are no other explicitly drawn internal lines or points. * **Labels and Annotations:** The figure is labeled as "(1)". **Textual Information:** 共有( 6 )个三角形 (Translation: There are a total of ( 6 ) triangles) *The number "6" is handwritten in the blank space.* **Interpretation for the count of 6 triangles:** In common "count the triangles" problems with this figure, the horizontal line segment (base) is implicitly considered to be divided into two smaller segments by a central, un-drawn point. If there are 3 points on this horizontal base (left, implicit center, right), it creates 2 segments. For the top half of the rhombus, with the top vertex as the apex, these 2 segments form (1+2) = 3 triangles. Similarly, for the bottom half of the rhombus, with the bottom vertex as the apex, another (1+2) = 3 triangles are formed. Adding these gives a total of 6 unique triangles (3 from the top apex, 3 from the bottom apex). --- **Sub-question (2):** **Chart/Diagram Description:** * **Type:** Geometric figure (a rhombus or diamond shape). * **Main Elements:** * The outer boundary forms a rhombus, with a top, bottom, left, and right vertex. * Two internal line segments are drawn: a horizontal one connecting the left and right vertices (a diagonal), and a vertical one connecting the top and bottom vertices (the other diagonal). These two diagonals intersect at the center of the rhombus. * **Labels and Annotations:** The figure is labeled as "(2)". **Textual Information:** 共有( 14 )个三角形 (Translation: There are a total of ( 14 ) triangles) *The number "14" is handwritten in the blank space.* **Interpretation for the count of 14 triangles:** This figure is a rhombus with its two diagonals. A standard count for this exact configuration (rhombus with two diagonals) typically yields 8 unique triangles (4 small triangles around the center, and 4 larger triangles each formed by two small ones, using one of the full diagonals as a side). However, the handwritten answer "14" suggests a different or more complex counting rule, common in such puzzles: * **Method 1 (Counting from each apex to segmented base):** * Consider the horizontal diagonal as a base. It is divided into 2 segments by the vertical diagonal. From the top vertex, 3 triangles are formed (1+2 segments). From the bottom vertex, 3 triangles are formed. (Total 6 triangles from horizontal base). * Consider the vertical diagonal as a base. It is divided into 2 segments by the horizontal diagonal. From the left vertex, 3 triangles are formed. From the right vertex, 3 triangles are formed. (Total 6 triangles from vertical base). * Summing these counts (6 + 6 = 12) identifies 12 unique triangles in this figure. * **Method 2 (Common solution for 14 in similar figures):** The number 14 for this shape often arises if the segments on each diagonal are implicitly considered to be 3 (i.e., each diagonal has 2 internal points dividing it into 3 segments) and triangles are counted systematically from each apex to these segments. However, the visible drawing does not show these additional internal points. Another common way to get 14 for similar figures involves additional lines not explicitly drawn here or a specific counting convention where certain overlapping triangles are counted in a way that leads to this sum. Given the visual simplicity, the 14 is likely derived from a specific pedagogical convention for counting triangles in such diagrams.