理解角（11岁以上）
Understanding angles (age 11+)
应用同一点处各角之和为360°、直线上各角之和为180°以及对顶角相等的性质，在多步问题中逐步求出未知角。
Apply the properties of angles at a point (360°), on a straight line (180°), and vertically opposite angles to find unknown angles in multi-step problems
学习证据 / Evidence
- 利用直线上各角之和为180°的性质，求出一个未知角。
- 运用对顶角相等的性质，建立并求解含未知角的方程。
- 在同一个图形中综合运用多个角度性质，分步求出多个未知角。
- Find a missing angle using the fact that angles on a straight line sum to 180°
- Use vertically opposite angles are equal to set up and solve an equation for an unknown
- Combine multiple angle facts in a single diagram to find several missing angles step by step
评估问题 / Assessment
如果给{{name}}一个图，图中交叉线上标有一些角和未知角，{{name}}能否利用直线和交叉线的角度规则，一步步求出所有缺失的角？
If {{name}} is given a diagram with several angles marked at crossing lines and some unknown, can they use the rules about straight lines and crossing lines to find all the missing angles step by step?