Got this pattern in my head and I wanted to make it with as intuitive controls as possible. Everything starts from the origin, so use the Move Graphics View to relocate the start.
More GeoGebra at
Function, derivative and tangent line
Proof: Difference of two squares
Centres in a Triangle
testfileWed Oct 17 20:30:19 CEST 20180.046674271827526925
Bagels or Donuts - A Balanced Assessment Task