Help with Directional 2D Cone

I am prototyping a first attempt at a top down game and hope someone might point me to some code examples.

I have figured out how to create a simple 2D cone shape, but I am not sure how to center it in a particular direction. The cone will eventually indicate the direction, and margin of error for a ranged attack, centered in the opposite direction of another position set behind the cones origin. Much like lining up a telescope.

Of course, I have to start by simply being able to direct the cone to begin with… and so far, everything I have tried has failed pretty badly. I do not have a very strong grasp of trig, but I learn fast.

Here is my code:
It will draw a simple cone using LineRenderer quite well.

private void DrawLineCone(Transform origin, float angle, float radius)
	int points = 3;
	Range = radius;

	float radian = angle * Mathf.Deg2Rad;
		//Debug.Log("Rad:	" + radian + " Angle:	" + (Mathf.Rad2Deg * radian) );
	float radianFract = radian / (float)points;
		//Debug.Log("Fract:	" + radianFract);
	Vector3 center = origin.transform.position;	//Where unit stands
	lineRenderer.SetVertexCount(points + 3);	//Add start/finish points

	Vector3 vect = center;	//Start point is center point.
		lineRenderer.SetPosition(0, vect);

	for(int x = 0; x < points + 1; x++)
		vect = center;
			vect.x += (float)(Math.Cos(radianFract * x) * Range);
			vect.z += (float)(Math.Sin(radianFract * x) * Range);

		lineRenderer.SetPosition(x + 1, vect);	//Skip first/last points.
	vect = center;
	lineRenderer.SetPosition(points + 2, vect);	//Last point is center point.

Have the cone pointing away from you on the Z axis. Then use: