GoGeometry Action 168!

Topic:
Geometry
Creation of this resource was inspired by a problem posted by Antonio Gutierrez. You can move the 2 LARGE WHITE POINTS anywhere you'd like at any time. Key Questions: 1) How do we know the octagon shown is a regular octagon? Explain. 2) Suppose each side of the octagon has length a. How can we write the length of the purple segment as a function of a? That is, how can we write the length of the purple segment in terms of a? 3) How can we formally prove the phenomenon dynamically illustrated here?

Quick (Silent) Demo