print("Insert length of proposed triangle: ") x = float(input("x = ")) y = float(input("y = ")) z = float(input("z = ")) if x+y>z and x+z>y and y+z>x: print("The triangle of xyz exist") else: print("The triangle does not exist")

Output:
Insert length of proposed triangle: 
Insert length of proposed triangle: 
Insert length of proposed triangle: 