from tkinter import *
import webbrowser
import math
root = Tk()
root.geometry("400x300")
root.resizable(0, 0)
root.config(bg="#d9ead3")
root.title("Calcular a àrea de meio Semicírculo")

def limpar():
    lado_entrada.delete(0, END)
def app():
    l =lado.get()
    raio = l/2
    b = math.pi* math.pow(raio,2)
    a = b/2
    arr = round(a,2)
    resultado.set(arr)
titulo = Label(text="Calcular a àrea de meio Semicírculo",
               font=("Arial", "15", "bold"),bg="#d9ead3",fg="#bf9000")
titulo.place(relx=0.08, rely=0.05)
texto_sub1  = Label(text="Altura:",
                    font=("Arial", "15", "bold"),bg="#d9ead3",fg="#bf9000")
texto_sub1.place(relx=0.2, rely=0.25)
lado = DoubleVar()
lado_entrada = Entry(textvariable=lado,
                                  font=("Arial", "12", "bold"),
                                  bg="white", fg="blue", justify='center')
lado_entrada.place(relx=0.45, rely=0.25, relwidth=0.3)

but1 = Button(text="Calcular", bd=2, bg='#107db2', fg='white',
              font=('verdana', 12, 'bold'), command=app)
but1.place(relx=0.15, rely=0.5, relwidth=0.35, relheight=0.1)

but_limpar = Button(text="Limpar", bd=2, bg='#107db2', fg='white',
                    font=('verdana', 12, 'bold'), command=limpar)
but_limpar.place(relx=0.55, rely=0.5, relwidth=0.35, relheight=0.1)

texto_sub2  = Label(text="Área do Semicírculo :",
                    font=("Arial", "12", "bold"),bg="#d9ead3",fg="#bf9000")
texto_sub2.place(relx=0.10, rely=0.75)
resultado = StringVar()
resultado_area = Label(textvariable=resultado,
                           font=("Arial", 12, "bold"), bg="#f0f8ff")
resultado_area.place(relx=0.55, rely=0.75, relwidth=0.35)
def site():
    new = 2
    url = "https://pt.wikihow.com/Encontrar-a-%C3%81rea-de-um-Semic%C3%ADrculo#:~:text=A%20%C3%A1rea%20de%20um%20semic%C3%ADrculo%20%C3%A9%20(1%2F2)(,pi)(r%5E2)."
    webbrowser.open(url)

menubar = Menu(root)
file = Menu(menubar, tearoff = 0)
menubar.add_cascade(label ='Opções', menu = file)
file.add_command(label ='Informação de Semicírculo', command=site)
file.add_command(label='Exit', command=root.destroy)
root.config(menu = menubar)
root.mainloop()