// Adds a lineRenderer to this transform and
    // Converts the line Renderer into a triangle.
    function Start() {
        var lineRenderer : LineRenderer = gameObject.AddComponent(LineRenderer);
        lineRenderer.SetWidth(0,3);
    }

using UnityEngine;
using System.Collections;

public class example : MonoBehaviour {
    void Start() {
        LineRenderer lineRenderer = gameObject.AddComponent<LineRenderer>();
        lineRenderer.SetWidth(0, 3);
    }
}

import UnityEngine
import System.Collections

class example(MonoBehaviour):

    def Start():
        lineRenderer as LineRenderer = gameObject.AddComponent[of LineRenderer]()
        lineRenderer.SetWidth(0, 3)