FA-5831 / Planar geometry / Open access
Regular polygon exterior angle · case 01
The interior angle is returned instead of its exterior turn.
ROOT CAUSE
The interior angle is returned instead of its exterior turn.
VERIFIED REPAIR
Apply the specified mathematical contract directly, preserving all terms and boundary cases: return 360/n
Unsuccessful approach: The full turn is halved.
Case contract
Integer coordinates and lengths, with exact arithmetic except for indicated division results. Lengths are nonnegative. Rectangles are (xmin,ymin,xmax,ymax) with ordered bounds; coordinate vectors have matching dimensions. Regular polygon exterior angle. Exact operational definition: 360/n
Why this case matters
Small exact fixtures expose this error without platform timing, external services, or probabilistic observations. Planar geometry results depend on the stated convention.
1 / The failure
Exit 1"""Failure Map reference implementation. Python standard library only."""
import json
import math
import calendar
import statistics
import itertools
from fractions import Fraction
from datetime import date, datetime, timedelta, timezone
from decimal import Decimal, ROUND_HALF_UP, ROUND_DOWN, ROUND_CEILING, ROUND_FLOOR
N = 1
observations = []
def solve(n):
return 180*(n-2)/n
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('fixture 1: (3,)', solve(*(3,)), 120)
check('fixture 2: (4,)', solve(*(4,)), 90)
check('fixture 3: (6,)', solve(*(6,)), 60)
check('fixture 4: (8,)', solve(*(8,)), 45)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
| Boundary fixture | Actual | Expected | Outcome |
|---|---|---|---|
| fixture 1: (3,) | 60.0 | 120 | Failed |
| fixture 2: (4,) | 90.0 | 90 | Passed |
| fixture 3: (6,) | 120.0 | 60 | Failed |
| fixture 4: (8,) | 135.0 | 45 | Failed |
SHA-256 / ac3af2694adb8473c01837e0cc266debfb43f05a7c228fcad703361a15a987fa
2 / The unsuccessful fix
Exit 1"""Failure Map reference implementation. Python standard library only."""
import json
import math
import calendar
import statistics
import itertools
from fractions import Fraction
from datetime import date, datetime, timedelta, timezone
from decimal import Decimal, ROUND_HALF_UP, ROUND_DOWN, ROUND_CEILING, ROUND_FLOOR
N = 1
observations = []
def solve(n):
return 180/n
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('fixture 1: (3,)', solve(*(3,)), 120)
check('fixture 2: (4,)', solve(*(4,)), 90)
check('fixture 3: (6,)', solve(*(6,)), 60)
check('fixture 4: (8,)', solve(*(8,)), 45)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
| Boundary fixture | Actual | Expected | Outcome |
|---|---|---|---|
| fixture 1: (3,) | 60.0 | 120 | Failed |
| fixture 2: (4,) | 45.0 | 90 | Failed |
| fixture 3: (6,) | 30.0 | 60 | Failed |
| fixture 4: (8,) | 22.5 | 45 | Failed |
SHA-256 / 2cdc1f3a7b1508ae5ac8f2e2c7b3849d3c9d33b8be641dae30fb9bbbdc9e12ef
3 / The verified repair
Exit 0"""Failure Map reference implementation. Python standard library only."""
import json
import math
import calendar
import statistics
import itertools
from fractions import Fraction
from datetime import date, datetime, timedelta, timezone
from decimal import Decimal, ROUND_HALF_UP, ROUND_DOWN, ROUND_CEILING, ROUND_FLOOR
N = 1
observations = []
def solve(n):
return 360/n
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('fixture 1: (3,)', solve(*(3,)), 120)
check('fixture 2: (4,)', solve(*(4,)), 90)
check('fixture 3: (6,)', solve(*(6,)), 60)
check('fixture 4: (8,)', solve(*(8,)), 45)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
| Boundary fixture | Actual | Expected | Outcome |
|---|---|---|---|
| fixture 1: (3,) | 120.0 | 120 | Passed |
| fixture 2: (4,) | 90.0 | 90 | Passed |
| fixture 3: (6,) | 60.0 | 60 | Passed |
| fixture 4: (8,) | 45.0 | 45 | Passed |
SHA-256 / c19169058e47dc25b7270c1e94bb7d0f6c48a0f33df61d0374378449808174f0
Verification & scope
This reproducer isolates one failure mechanism. Results cover the supplied fixtures. Variants within a family share a test contract and should remain grouped when constructing evaluation splits. Related mechanisms with a shared evaluation_group must also remain together; these controlled models are not independent production incidents.
Observations recorded using Python 3.12.14 at 2026-09-29T14:37:54.332891+00:00.
Case digest / 75420bc96ae7c9d65e553c05ceeac19d8cf76c16da1feaae8cb74e1bebc508f1