Nach deine Zeichnung gilt
tan(α) = h / x → h = x * tan(α)
tan(β) = h / (x + 1300) → h = (x + 1300) * tan(β)
Gleichsetzen
x * tan(α) = x * tan(β) + 1300 * tan(β)
x * tan(α) - x * tan(β) = 1300 * tan(β)
x * (tan(α) - tan(β)) = 1300 * tan(β)
x * (tan(α) - tan(β)) = 1300 * tan(β)
x = 1300 * tan(β) / (tan(α) - tan(β))
h = x * tan(α)
h = 1300 * tan(α) * tan(β) / (tan(α) - tan(β))
Einsetzen
6 + 2/60 + 28.73/3600 = 6.041313888°
5 + 54/60 + 50.81/3600 = 5.914113888°
h = 1300 * tan(6.041313888°) * tan(5.914113888°) / (tan(6.041313888°) - tan(5.914113888°)) = 6350.070489
Dazu kommt dann noch die Höhe des Meeresspiegels.