1012 solve

def calculate(a,b,c):
    pi=3.14159
    tri=.5 *a *c
    tre = print("triangle: ", "{:.3f}".format(tri))
    d=pi * (c * c)
    da=print("circulo: ","{:.3f}".format(d))
    tra=(a+b)/2*c
    tra1=print("trapezio: ","{:.3f}".format(tra))
    s=b*b
    s1=print("quadrado: ","{:.3f}".format(s))
    r=a*b
    r1=print("retangulo: ","{:.3f}".format(r))
    return da,tre,tra1,s1

calculate(float(input()),float(input()),float(input()))