I am looking for explanation about the true darts tools. I found some explanations in dismine / Valentina / issues / #301 - True darts — Bitbucket

I know it requires 5 points:

- 1 and 2 on the base line
- 3 at the left top of the V
- 4 at the bottom edge of the V
- 5 at the right top of the V

It generates 2 points D1 and D2 to make the dart.

Is the geometry defined by these conditions:

- |P4 D1| = |P4 D2|
- angle(P1 D1, D1 P4) + angle(P2 D2, D2 P4) = 180°