三角形与多边形的内角和
Angle sums in triangles and polygons
推导并运用三角形内角和为180°这一性质，由此推算任意多边形的内角和为(n−2)×180°，并会计算正多边形的内角和外角。
Derive and use the angle sum in a triangle (180°), use it to deduce the angle sum in any polygon ((n−2) × 180°), and calculate interior and exterior angles of regular polygons
学习证据 / Evidence
- 用180°减去已知的两个角，求出三角形中缺失的角。
- 将六边形分割成三角形，求出六边形的内角和。
- 已知正多边形的边数，计算它的每个内角和外角。
- Calculate a missing angle in a triangle by subtracting the known angles from 180°
- Find the sum of interior angles in a hexagon by dividing it into triangles
- Calculate each interior and exterior angle of a regular polygon given the number of sides
评估问题 / Assessment
如果{{name}}已知一个三角形的两个角分别是50°和70°，能求出第三个角吗？还能求出正五边形的每个内角吗？
If {{name}} knows two angles of a triangle are 50° and 70°, can they work out the third? And can they figure out the angles inside a regular pentagon?