import math
epsilon = 1E-10
a = float(input())
b = float(input())
c = float(input())
if (a + b > c and b + c > a and c + a > b):
    p = (a + b + c)/2
    s = round(math.sqrt(p*(p-a)*(p-b)*(p-c)), 2)
    if (a == b or b == c or c == a):
        if (a == b and b == c):
            print("Tam giac deu, dien tich = %g" % s)
        else:
            print("Tam giac can, dien tich = %g" % s)
    elif (abs(a*a + b*b - c*c) < epsilon or abs(b*b + c*c - a*a) < epsilon or abs(c*c + a*a - b*b < epsilon)):
        print("Tam giac vuong, dien tich = %g" % s)
    else:
        print("Tam giac thuong, dien tich = %g" % s)
else:
    print("Khong phai tam giac")