A straight angle of 180 degree

						var board = JXG.JSXGraph.initBoard('box1', {
boundingbox: [-10, 10, 10, -10],showNavigation:false, showcopyright: false, axis: false,
});

var p1 = board.create('point', [-3.5, -2.0],{name:'',face:''});
var p2 = board.create('point', [3.5, -2.0],{name:'',face:''});
var l1 = board.create('line', [p1,p2]);
var p3 = board.create('point', [0, -2],{name:'',},{name:'',face:''});



var a1 = board.create('angle', [p2, p3, p1],{radius:2.5,name:"180°",label:{offset:[-12,-25]}});

The image appears in the following posts

The angle is one of the important concepts in geometry. An angle is formed when two lines intersect, or by a ray rotating around a fixed endpoint (common vertex). The ray is called the initial arm or the beginning side of the angle. The other side of the angle is called the terminal arm, or terminal side. Angles appear in variety of geometrical shapes, triangle, polygons, circles, etc. Understanding the types of angles is the beginning of deep dive of more complex angle related questions.

Triangle posted 1 year ago