Catriona's Angle on Tangent Circles
Another great Catriona Agg puzzle with a degree of freedom. I think the angle is going to be constant for any isosceles...
Original: https://twitter.com/Cshearer41/status/1322486941523300352
![Image](https://www.geogebra.org/resource/cwpuc6nn/Yrg5dd1CwH7WkQGT/material-cwpuc6nn.png)
Why is it constant?
Extension: what if it was not a right triangle?