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# i want to create a triangle from 2 3d vectors

Hi i am trying to do a triangle from 2 given 3d vectors and i want the triangle to be symetrical and i dont know how to get the last 3d vector

and with symetrical i mean the sides are equal length

Well the third vector (lets call it C) in a triangle is always C= A+B This assumes that the first is A and the second is B.

If you want a triangle with equal long sides then you have to have an angle of 60° between the first 2 vectors or this is not possible. (assuming that you want all sides to be equally long) If only 2 sides have to be equally long let me know. That is easier done.

**Answer** by myzzie
·
May 04, 2019 at 03:18 PM

There is no last vector, what you're looking for is a circle. Then you can define where in that circle you want to put your last point.

```
Vector3 dir = (B-A).normalized;
float dist = Vector3.Distance(A, B);
Vector3 perp = Vector3.Cross(dir, Vector3.up).normalized;
C = Quaternion.AngleAxis(60, perp) * dir * dist;
```

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