Creation of this activity was inspired by a [url=https://twitter.com/CutTheKnotMath/status/996023102147571712]problem[/url] posted by [url=https://twitter.com/CutTheKnotMath]Alexander Bogomolny[/url]. [br][br]Shown below is a circle with a chord. The chord has [b][color=#ff00ff]pink endpoints[/color][/b]. [br]The [b][color=#38761d]green point is any point[/color][/b] on this chord. [br]The [b][color=#38761d]green segment displayed[/color][/b] illustrates the [b][color=#38761d]shortest distance[/color][/b] from the [b][color=#38761d]green point[/color][/b] to the circle itself. [br][br]Feel free to move these [b]LARGE POINTS[/b] anywhere you'd like [b]AT ANY TIME.[/b] [br][br][b]Challenge:[/b][br]Given the circle has [b]radius [i]r[/i][/b], express the [b][color=#38761d]length of the green segment[/color][/b] solely as a function of [i]r [/i](regardless of [b][color=#38761d]green point[/color][/b]'s location on the chord itself).