Major Arc -- from Wolfram MathWorld

A major arc (right figure) is an arc of a circle having measure greater than or equal to 180 degrees (pi radians).

Ellipse（椭圆）-云社区-华为云

A matryoshka of Brocard porisms European Journal of Mathematics

Ellipse（椭圆）_51CTO博客_椭圆a

Minor Arc -- from Wolfram MathWorld

wiskundeleraar

Mathematics, Free Full-Text

College students: Hilarious pictures drawn on hw/exams makes

Circular sector, Math Wiki

Trisection of angles-similarly

Arc length - Wikipedia

Arc Length and Surface Area Calculus Techniques Meet History - ppt