"""
Calculates the area of a triangle using Heron's formula:

A = one quarter times the square root of (4 (side1 squared * side2 squared + side1 squared * side3 squared = side2 squared * side3 squared) - the square of(side1 squared + side2 squared + side3 squared))

Author: Adriana Ferraro (afer023)
"""
import math

side1 = 4
side2 = 7
side3 = 9



print("Length of sides: ", side1, ', ', side2, ' and ', side3, sep = "")
print("Area:", area)