<human>:  math fuction for area of triangle.
<bot>: Here is a Python function to calculate the area of triangles

import math

def area_of_triangle(a,b,c):
  """
  >>> area_of_triangle(3,4,5)
  12
  """
  s = (a+b+c)/2
  return s*(s-a)*(s-b)*(s-c)

# Enter the numbers
a = 3
b = 4
c = 5

# Calling the function
print((area_of_triangle(a,b,c)))

#Example Output
# 36.0

#Remember to inspect code for bugs.