A geodesic triangle with oriented boundary yields a curve which is piecewise differentiable. Furthermore, the tangent vector varies continuously at all but the three corner points, where it changes suddenly. The angular difference of the tangent vectors at these corner points are called the jump angles.
Jump Angle
See also
Angular Defect, Gauss-Bonnet FormulaExplore with Wolfram|Alpha
Cite this as:
Weisstein, Eric W. "Jump Angle." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/JumpAngle.html