Visual Proof for Tiling by Regular Pentagons

(a) Drag the points on the sliders to visualize why tiling the plane works / doesn't work with these regular polygons.[br](b) How many polygons meet at each vertex?[br](c) What is the sum of the [color=#1551b5]angles[/color] meeting at the same vertex?[br][br][b]Regular Pentagon[/b]

Information: Visual Proof for Tiling by Regular Pentagons