[RequireComponent(typeof(Image))]
class rotation : MonoBehaviour
{
    [SerializeField]
    private float left = 180f, up = 0f;

    private void OnDrawGizmosSelected()
    {
        RectTransform rect = GetComponent<RectTransform>();

        Vector3[] corners = new Vector3[4];
        rect.GetWorldCorners(corners);
        float rot = transform.eulerAngles.z;

        Gizmos.color = Color.red;
        Gizmos.DrawLine(corners[3], corners[3] +
            new Vector3(Mathf.Cos((left + rot) * Mathf.Deg2Rad) * rect.rect.width,
            Mathf.Sin((left + rot) * Mathf.Deg2Rad) * rect.rect.height));

        Gizmos.color = Color.blue;
        Gizmos.DrawLine(corners[3], corners[3] +
            new Vector3(Mathf.Cos((up + rot) * Mathf.Deg2Rad) * rect.rect.width,
            Mathf.Sin((up + rot) * Mathf.Deg2Rad) * rect.rect.height));
    }
}