Exercise 3.5 - Circles tangent to a given line and passing by two points

Steps 17 (par 14)
The square on CG and CG' is equal to CA x CB, by the construction in II.14. Then CG is tangent at G by III.37
– Gianluca Occhetta

Information: Exercise 3.5 - Circles tangent to a given line and passing by two points