Write a Python program to find the area of a triangle given its lengths of sides.
a = 7, b = 6, c = 8
def triangle_area(a, b, c): 
	s = (a + b + c) / 2
	return (s*(s-a)*(s-b)*(s-c)) ** 0.5

result = triangle_area(7, 6, 8)
print(result)