Write a function to find the perimeter of a triangle.
def perimeter_triangle(a,b,c):
  perimeter=a+b+c
  return perimeter
<s>[INST]<<SYS>>Given a task and its code, generate test cases for the code.<</SYS>>Write a function to find the perimeter of a triangle.
def perimeter_triangle(a,b,c):
  perimeter=a+b+c
  return perimeter[/INST]assert perimeter_triangle(10,20,30)==60
assert perimeter_triangle(3,4,5)==12
assert perimeter_triangle(25,35,45)==105</s>