Chord and rise from radius and angle

Code snippets

curl "https://api.oanor.com/arch-api/v1/from-radius-angle" \
  -H "x-oanor-key: oanor_test_..."

await fetch("https://api.oanor.com/arch-api/v1/from-radius-angle", {
  headers: { "x-oanor-key": "oanor_test_..." }
});

$ch = curl_init("https://api.oanor.com/arch-api/v1/from-radius-angle");
curl_setopt($ch, CURLOPT_HTTPHEADER, ["x-oanor-key: oanor_test_..."]);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
$out = curl_exec($ch);

import requests
requests.get(
    "https://api.oanor.com/arch-api/v1/from-radius-angle",
    headers={"x-oanor-key": "oanor_test_..."}
)

Example response

A real response from this endpoint, captured by the latest health check.

{
    "data": {
        "note": "From a radius and the central angle it subtends: the chord (the span) = 2·R·sin(angle/2), the rise (sagitta) = R·(1 − cos(angle/2)), the arc length = R·angle, and the segment area below the chord. This is the inverse of span-and-rise — useful when the curve is struck from a known radius, as with a trammel or a router on a pivot.",
        "inputs": {
            "radius_m": 1.25,
            "central_angle_deg": 106.2602
        },
        "rise_m": 0.5,
        "arc_length_m": 2.3182,
        "chord_span_m": 2,
        "segment_area_m2": 0.6989
    },
    "meta": {
        "timestamp": "2026-06-07T08:17:54.914Z",
        "request_id": "9271bc2b-5185-44f5-843a-30ade1117437"
    },
    "status": "ok",
    "message": "From radius and angle",
    "success": true
}