public SketchPoint addPoint(SketchLine sl1, SketchLine sl2)
{
Vector2d v1 = addVec(sp, sl1), v2 = addVec(sp, sl2);
pt = sp.Geometry.Copy();
v1.AddVector(v2);
v1.ScaleBy(0.4);
pt.TranslateBy(v1);
return(ps.SketchPoints.Add(pt));
}