坐标（12岁及以上）
Coordinates (age 12+)
理解相似是指一个图形是另一个图形按比例放大得到的关系；会按给定的比例因子和放大中心构造相似图形，并能在有坐标格和无坐标格的情况下完成。
Understand similarity as a relationship where one shape is an enlargement of another; construct similar shapes by enlargement with a given scale factor and centre, with and without coordinate grids
学习证据 / Evidence
- 按照给定的比例因子和指定的放大中心放大一个图形
- 通过比较两个相似图形的对应边，确定它们之间的比例因子
- 解释为什么相似图形的对应角相等，而对应边成比例
- Enlarge a shape by a given scale factor from a specified centre of enlargement
- Determine the scale factor between two similar shapes by comparing corresponding sides
- Explain why corresponding angles in similar shapes are equal while sides are in proportion
评估问题 / Assessment
如果{{name}}想把一张照片放大到原来的三倍，能算出新的尺寸吗？并且能说明形状保持不变，只是所有长度都按相同的倍数增大了吗？
If {{name}} wants to enlarge a photo so it's three times bigger, can they work out the new dimensions — and explain that the shape stays the same but all lengths increase by the same factor?