Sorry to be a nuisance. It seems that my problem arises from the last three lines. I am not sure why.I get the message.

"Oops, try again. Did you create an instance of Triangle called my_triangle?"

I know mu code is not elegant

```
class Triangle(object):
number_of_sides = 3
def check_angles(self, angle1, angle2, angle3, total ):
self.angle1 = angle1
self.angle2 = angle2
self.angle3 = angle3
self.total =angle1+angle2+ angle3
if total==180:
return true
else:
return false
my_triangle = Triangle(35, 55, 90)
print my_triangle.number_of_sides
print my_triangle.check_angles(35, 55, 90)
```