什么是角？
What Is an Angle?
理解角是由两条共用一个端点（顶点）的射线形成的几何图形；能在实际生活情境和二维图形中辨认角。
Understand that an angle is a geometric shape formed by two rays sharing a common endpoint (vertex); recognise angles in real-life contexts and 2-D shapes
学习证据 / Evidence
- 在图中辨认角的顶点和两条边
- 在教室里找出角的实例（如打开的门、钟表的指针）
- 解释为什么两条射线交于一点能形成一个角
- Identify the vertex and arms of an angle in a diagram
- Find examples of angles in the classroom (e.g. open door, clock hands)
- Explain why two rays meeting at a point form an angle
评估问题 / Assessment
如果你在纸上画出两条从同一点出发的线，{{name}}能告诉你它们之间的空间就是一个角，并指出它们相交的顶点吗？
If you draw two lines starting from the same point on paper, can {{name}} tell you that the space between them is an angle — and point to the vertex where they meet?