Google Classroom
GeoGebraGeoGebra Classroom

for intersecting lines,vertically opposite angles are equal

We can see a line segment AB in black color and a point E is in present on it. Line segment EC is drawn at an angle β with AE (in anti clock direction) and a line segment ED is drawn at an angle α with EB (in anti clock direction). We can change the values of α and β using their respective slide bars. We can also move the points A, B and E. Let us move these free points and change the values of the angles and see how the lines change.