# -*- coding: utf-8 -*-
# Calcul inverse de la tangente
# v.3

from math import atan

print("Calcul de arc tangente en degrés")
print("---------------------------------")
pi = 3.1415926535897932384626433832795
# tan 1 = 45
# tan 360 = 0
# pour le test arc tangente de 20° = 0.36397023426620234

ata = input ("Entrer l'arctangente ? ")

if ata < "0" or ata > "58" or ata >= "100" :
    print()
    print("Entrée non valide")
    ata = 0

try :
    ata = float(ata)
except :
    print("Utilisons 0.36397023426620234")
    ata = "0.36397023426620234"
    ata = float(ata)

angr = atan(ata)         # calcul de l'arc-tangente en radians
angd = angr / pi * 180   # convertion des radians en degrés

print()
print("l'arc-tangeante de", ata, "est de", round(angd, 2), "degrés")
print (angd)
print()

print()
print("----------------------")
bye = (input ("Entrer pour Sortir...!"))