curl --request POST \
  --url https://api.iotools.cloud/v1/tool/tangent-line-to-circle-calculator \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "centerX": "0",
  "centerY": "0",
  "radius": "5",
  "pointX": "13",
  "pointY": "0"
}
'

{
  "tool": "tangent-line-to-circle-calculator",
  "tool_version": "1.0.2",
  "outputs": {
    "results": [
      {
        "metric": "Distance to center",
        "value": "13"
      },
      {
        "metric": "Case",
        "value": "Point is outside the circle — two tangent lines"
      },
      {
        "metric": "Tangent length",
        "value": "12"
      }
    ],
    "tangentLines": [
      {
        "line": "Tangent 1",
        "equation": "y = -0.416667x + 5.41667",
        "point-of-tangency": "(1.92308, 4.61538)"
      },
      {
        "line": "Tangent 2",
        "equation": "y = 0.416667x - 5.41667",
        "point-of-tangency": "(1.92308, -4.61538)"
      }
    ]
  },
  "credits_used": 5,
  "credits_remaining": null
}