In my Computer Science class we were asked to make a UI that solves some problems. All of the buttons work, the math operations return the right answer, but when I try to make it pop up on the screen, It doesn't work.

Here's My Code (sorry some parts are in french):

from tkinter import *
from math import sqrt
root = Tk()
root.title("CALCULS")
root.geometry("400x300")
vala = "unset"
valb = "unset"
svala = 0
svalb = 0
valtot = "Pas de valeurs"
def updateresult():
 printedvaltot.place(x = 60, y = 250, width = 120, height = 20)
def calculer1():
 vala = float(entryvala.get())
 valb = float(entryvalb.get())
 svala = vala**2
 svalb = valb**2
 valtot = svala - svalb
 updateresult()
def calculer2():
 vala = float(entryvala.get())
 valb = float(entryvalb.get())
 valtot = vala + valb
 valtot = valtot**2
 updateresult()
def calculer3():
 vala = float(entryvala.get())
 valb = float(entryvalb.get())
 valtot = vala - valb
 valtot = valtot**2
 updateresult()
def calculer4():
 vala = float(entryvala.get())
 valb = float(entryvalb.get())
 valtot = vala*valb
 valtot = sqrt(valtot)
 updateresult()
 
#TEXTE
printed1 = Label(root, text = "Choisissez une valeur pour a et b, et une opération", foreground = "#297294")
printed1.place(x = 60, y = 20)
printedvala = Label(root, text = "Valeur de a", background = "#297294")
printedvala.place(x = 60, y = 50, width = 120, height = 20) 
printedvalb = Label(root, text = "Valeur de b", background = "#297294")
printedvalb.place(x = 60, y = 80, width = 120, height = 20)
printedvaltot = Label(root, text = str(valtot))
printedvaltot.place(x = 200, y = 250, width = 120, height = 20)
printedresultat = Label(root, text = "RESULTAT", background = "#297294")
printedresultat.place(x = 60, y = 250, width = 120, height = 20)
#INPUT
entryvala = Entry(root)
entryvala.place(x = 200, y = 50, width = 120, height = 20)
entryvalb = Entry(root)
entryvalb.place(x = 200, y = 80, width = 120, height = 20)
#BOUTONS
b1 = Button(root, command = calculer1, text = "a2-b2")
b1.place(x = 60, y = 110, width = 120, height = 20)
b2 = Button(root, command = calculer2, text = "(a+b)2")
b2.place(x = 200, y = 110, width = 120, height = 20)
b3 = Button(root, command = calculer3, text = "(a-b)2")
b3.place(x = 60, y = 140, width = 120, height = 20)
b4 = Button(root, command = calculer4, text = "√(a*b)")
b4.place(x = 200, y = 140, width = 120, height = 20)

All of it works, except the updating label part. HELP!!

I tried remaking it from scratch, didn't work. I tried using the strvar method, didn't work. I tried using textvariable for this specific label, still didn't work.