多边形周长
Perimeters of polygons
解决与多边形周长相关的问题：根据边长求周长，求未知边长，并探索周长相同但面积不同的长方形（或面积相同但周长不同的长方形）。
Solve problems involving perimeters of polygons: find perimeter from side lengths, find an unknown side length, and explore rectangles with same perimeter but different areas (or vice versa)
学习证据 / Evidence
- 计算边长为8厘米和5厘米的长方形的周长
- 已知一个五边形的周长是30厘米，且其中四条边已知，求未知边的长度
- 画出两个周长都为24厘米但面积不同的长方形
- Calculate the perimeter of a rectangle with sides 8 cm and 5 cm
- Find the missing side of a pentagon with perimeter 30 cm and four known sides
- Draw two rectangles both with perimeter 24 cm but different areas
评估问题 / Assessment
如果一个长方形的周长是24厘米，其中一条边是8厘米，{{name}}能不能不画图就算出另一条边的长度？
If a rectangle has a perimeter of 24 cm and one side is 8 cm, can {{name}} work out the length of the other side — without drawing it?