curl --request POST \
  --url https://api.iotools.cloud/v1/tool/frustum-calculator \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "radius1": "5",
  "radius2": "3",
  "height": "10",
  "precision": "4"
}
'

{
  "tool": "frustum-calculator",
  "tool_version": "1.0.2",
  "outputs": {
    "slantHeight": "10.198",
    "volume": "513.1268",
    "lateralArea": "256.3047",
    "totalArea": "363.1188",
    "result": [
      {
        "property": "Slant height (l)",
        "value": "10.198"
      },
      {
        "property": "Volume",
        "value": "513.1268"
      },
      {
        "property": "Lateral surface area",
        "value": "256.3047"
      },
      {
        "property": "Top base area",
        "value": "78.5398"
      },
      {
        "property": "Bottom base area",
        "value": "28.2743"
      },
      {
        "property": "Total surface area",
        "value": "363.1188"
      }
    ],
    "steps": "r1 = 5, r2 = 3, h = 10\nl = √((r1 - r2)² + h²) = √((5 - 3)² + 10²) = 10.198\nV = (π·h/3) · (r1² + r1·r2 + r2²) = (π × 10/3) × (5² + 5×3 + 3²) = 513.1268\nLateral area = π · (r1 + r2) · l = π × (5 + 3) × 10.198 = 256.3047\nTotal area = Lateral area + π·r1² + π·r2² = 256.3047 + 78.5398 + 28.2743 = 363.1188"
  },
  "credits_used": 5,
  "credits_remaining": null
}