the assumption here being that both lines JH and FH are tangent lines to the circle, if that's the case the external angle of 34° is the angle made by the equal tangents, meaning the triangle is an isosceles with twin sides.
In an isosceles triangle the twin sides make also twin angles, so the angles at J and F are twins, and they'd be 180° - 34° = 146° total, since they're twins, each one takes half, or 73°.