A satisfying geometry question - circle exterior to a triangle side

Thanks to Amit from India for the suggestion! A circle is tangent on the exterior of a side of a triangle and tangent to the lines through the other two sides. The tangent side length 7, and the other side lengths are 8 and 9. What is the radius of the circle? 0:00 Problem 1:22 Geometry 5:35 Trigonometry Twitter thread (additional solutions) Excircle formula Excircle formula Wikipedia #Exradii Tangent half-angle Subscribe: Send me suggestions by email (address at end of many videos). I may not reply but I do consider all ideas! If you purchase through these links, I may be compensated for purchases made on Amazon. As an Amazon Associate I