Posted by emge25 on Jun 18, 2020; 8:37pm
URL: https://forum.librecad.org/Tangent-Curve-between-existing-circle-and-line-tp5719065p5719101.html

the solution need some calculations
See the image
The center of arc is on the line AB
C, O and T are aligned
AB and OB are known
The radius of arc is the sum of CO and R
CO is calculated by Pytagore theorem
Finaly we obtain the équation at the bottom of the picture
Solving this équation is easy placing the square root in a side and the rest on the other by sqaring all. We obtain x = 262.5
The radius of the arc is 150 + 262.5
Point C is the center of the arc.