Beginner question - please help

I am asked this question as part of an assignment, and I have no clue what to say:

What is risky about the following and how could you rewrite it to make it safer?

Code:

---


class Line
{
    public:
          Point  p1;
          Point  p2;
          double length;
}

---

thank you all for your help.

It's missing a ; at the closing } but I don't think that's the point.

I think the issue here is encapsulation. You can set the values of all the variables cause they're defined as public members. There should be setter functions of some description which set the points and then recalculates the length between the points. If you have a point at (0,3) and another at (4,0) and the length between them as 5 and you were then to change the first point to (4,0), there's no way the code would change the length to zero. It would still say five. If you had a function which managed the changing of the variables it could calculate the new length on every change.

http://www.cprogramming.com/tutorial/lesson12.html

Class tutorial on public and private/protected definitions.