1. 所有些角
alternate angle内错角?
corresponding angle同位角?
vertical1 angle对顶角?
central angle 圆心角?
interior angle内角?
exterior2 angle外角?
supplementary3 angles补角?
complementary angle余角?
adjacent angle邻角?
acute angle锐角?
obtuse4 angle钝角?
right angle直角
round angle周角?
straight angle平角?
included angle夹角??
2. 所有些三角形
equilateral triangle等边三角形?
scalene triangle不等边三角形?
isosceles triangle等腰三角形?
right triangle直角三角形?
oblique斜三角形?
inscribed triangle内接三角形