这是北师大版小学五年级的教材，轴对称，讲解清析，深刻；结合生活，让小朋友能展开联想；多使用图形；图形要大一些---Here is the extracted content from the image: ## 轴对称再认识 (二) ### Task 1: Taoqi's House Drawing **Question Stem:** 淘气根据轴对称小房子的一半 (见图①) 画出了整座房子 (见图②), 他画得对吗？ *(Translation: Taoqi drew the whole house (see Figure ②) based on half of a small house (see Figure ①) using axis symmetry. Did he draw it correctly?)* **Other Relevant Text (Dialogue):** * **Girl character:** "淘气画好的房子对折后不能完全重合，他画的……" *(Translation: The house Taoqi drew cannot perfectly overlap when folded, what he drew is...)* * **Boy character:** "房子下边最左边一点到对称轴有2格，最右边也应该到对称轴有2格。" *(Translation: The leftmost point at the bottom of the house is 2 grids away from the axis of symmetry, the rightmost side should also be 2 grids away from the axis of symmetry.)* **Chart/Diagram Description:** * **Type:** Grid diagrams with geometric shapes (house outlines). Both grids are 6 cells wide by 6 cells high. * **Figure ① (Half House):** * **Main Elements:** A vertical dashed line serves as the axis of symmetry, located between the 1st and 2nd vertical grid lines from the left edge (i.e., between column 1 and column 2). * **Shape:** A "half-house" figure is drawn to the right of the dashed line. * **Vertices (using 1-indexed column/row, bottom-left cell is (1,1)):** * Base-left: (column 2, row 1) * Base-right: (column 4, row 1) * Right wall top: (column 4, row 3) * Roof peak: (column 3, row 5) * Left wall top: (column 2, row 3) * **Lines:** Connected as: (2,1)-(4,1)-(4,3)-(3,5)-(2,3)-(2,1). * **Figure ② (Full House):** * **Main Elements:** A full house figure is drawn. The implied axis of symmetry for this full house would be a vertical line between the 3rd and 4th vertical grid lines (i.e., between column 3 and column 4). * **Shape:** * **Vertices:** * Bottom-left outer: (column 1, row 1) * Bottom-right outer: (column 6, row 1) * Bottom-left inner: (column 2, row 1) * Bottom-right inner: (column 5, row 1) * Top-left outer wall: (column 1, row 3) * Top-right outer wall: (column 6, row 3) * Top-left inner wall: (column 2, row 3) * Top-right inner wall: (column 5, row 3) * Roof peak: (midpoint between column 3 and 4, row 5) * **Lines:** Forms a house with a base of 6 cells wide, 2 inner vertical lines forming a "doorway" of 3 cells wide, and a triangular roof peaking at row 5. ### Task 2: Drawing the Other Half **Question Stem:** 以虚线为对称轴，在方格纸上画出图形的另一半。 *(Translation: Using the dashed line as the axis of symmetry, draw the other half of the figure on the grid paper.)* **Chart/Diagram Description:** * **Type:** Grid diagram with a partial geometric shape. * **Elements:** * **Grid:** 6 cells wide by 6 cells high. * **Axis of Symmetry:** A vertical dashed line located between the 3rd and 4th vertical grid lines from the left edge (i.e., between column 3 and column 4). * **Partial Shape:** An "L" shaped figure is drawn on the left side of the dashed line. * **Lines:** * Vertical segment: From (column 2, row 3) to (column 2, row 5). * Horizontal segment: From (column 2, row 3) to (column 3, row 3). ### Hints for Axis Symmetry Drawing **Other Relevant Text (Dialogue):** * **Girl character:** "先想象一下对折的过程……" *(Translation: First, imagine the folding process...)* * **Boy character:** "先找到每条线段的端点，再找到这些点对称的点……" *(Translation: First, find the endpoints of each line segment, then find the points symmetric to these points...)* **Chart/Diagram Description (Hint 1 - Folding Process):** * **Type:** Two consecutive grid diagrams showing a shape's reflection through folding. * **First Grid (Left):** * **Grid:** 4 cells wide by 6 cells high. * **Axis of Symmetry:** A vertical dashed line between the 2nd and 3rd vertical grid lines from the left (i.e., between column 2 and column 3). * **Shape:** A "half-tree" figure drawn on the left side of the dashed line. * **Lines:** * Main vertical stem: From (column 2, row 1) to (column 2, row 6). * Upper left branch: From (column 1, row 4) to (column 2, row 5). * Lower left branch: From (column 1, row 2) to (column 2, row 3). * **Second Grid (Right):** * **Grid:** 4 cells wide by 6 cells high. * **Shape:** A complete "tree" figure, which is the symmetric reflection of the first grid's shape. The dashed line is no longer present, implying the "folding" is complete. **Chart/Diagram Description (Hint 2 - Point Reflection Process):** * **Type:** Two consecutive grid diagrams showing the process of reflecting points. * **First Grid (Left):** * **Grid:** 4 cells wide by 6 cells high. * **Axis of Symmetry:** A vertical dashed line between the 2nd and 3rd vertical grid lines from the left (i.e., between column 2 and column 3). * **Shape:** The same "half-tree" figure as in Hint 1, First Grid. * **Points:** Black dots are marked at the vertices and key points of the half-tree: (column 2, row 1), (column 1, row 2), (column 2, row 3), (column 1, row 4), (column 2, row 5), (column 2, row 6). * **Second Grid (Right):** * **Grid:** 4 cells wide by 6 cells high. * **Shape:** The same full "tree" figure as in Hint 1, Second Grid. * **Points:** All original points from the first grid and their symmetric reflected counterparts are marked with black dots. For example, the point (column 1, row 2) on the left has its symmetric point at (column 3, row 2) on the right. Points on the axis (e.g., (column 2, row 3)) are marked only once. ### Task 3: Drawing Axis-Symmetric Figures **Question Stem:** 以虚线为对称轴，画出下面图形的轴对称图形。 *(Translation: Using the dashed line as the axis of symmetry, draw the axis-symmetric figure for the shapes below.)* **Chart/Diagram Description (Left Task):** * **Type:** Grid diagram with a partial geometric shape. * **Elements:** * **Grid:** 6 cells wide by 6 cells high. * **Axis of Symmetry:** A vertical dashed line located between the 3rd and 4th vertical grid lines from the left edge (i.e., between column 3 and column 4). * **Partial Shape:** A "staircase" or "Z"-like figure is drawn on the left side of the dashed line. * **Lines:** * Vertical segment: From (column 2, row 3) to (column 2, row 4). * Horizontal segment: From (column 2, row 4) to (column 3, row 4). * Vertical segment: From (column 3, row 4) to (column 3, row 5). **Chart/Diagram Description (Right Task):** * **Type:** Grid diagram with a partial geometric shape. * **Elements:** * **Grid:** 6 cells wide by 6 cells high. * **Axis of Symmetry:** A horizontal dashed line located between the 3rd and 4th horizontal grid lines from the bottom edge (i.e., between row 3 and row 4). * **Partial Shape:** A figure resembling the bottom part of a '6' or a 'P' is drawn below the dashed line. * **Lines:** * Vertical segment: From (column 4, row 1) to (column 4, row 3). * Horizontal segment: From (column 4, row 1) to (column 5, row 1). * Vertical segment: From (column 5, row 1) to (column 5, row 2). * Horizontal segment: From (column 5, row 2) to (column 4, row 2).