# Refactor: delete GeoUtils.CalculatePolygonDiagonalDistance dead alias

**Task**: AZ-380_refactor_delete_polygon_diagonal
**Name**: Delete dead alias method
**Description**: Remove `GeoUtils.CalculatePolygonDiagonalDistance` — pure alias of `CalculateDistance` with no callers.
**Complexity**: 1 point
**Dependencies**: None (verify with one final grep before deletion)
**Component**: Common
**Tracker**: AZ-380
**Epic**: AZ-350

## Problem

`SatelliteProvider.Common/Utils/GeoUtils.cs:129-132` defines `CalculatePolygonDiagonalDistance(GeoPoint nw, GeoPoint se)` which simply returns `CalculateDistance(nw, se)`. Pure alias, no callers in the codebase. Adds API surface for nothing.

## Outcome

- Method removed.
- `dotnet build` succeeds across all consumers.
- 37 unit + 5 smoke tests stay green.

## Scope

### Included
- Verify with `grep -r "CalculatePolygonDiagonalDistance"` that no caller exists outside the implementation.
- Delete the method.

### Excluded
- Replacing it with anything (no caller wants it).

## Acceptance Criteria

**AC-1: Method gone**
Given the post-refactor source
When grepped for `CalculatePolygonDiagonalDistance`
Then matches are confined to docs (which should be cleaned up if they describe the method as live).

**AC-2: Build succeeds**
Given the post-refactor solution
When `dotnet build` runs
Then it succeeds with zero errors.

**AC-3: Tests stay green**
Given the post-refactor build
When `scripts/run-tests.sh --smoke` runs
Then all 37 unit + 5 smoke scenarios pass.

## Constraints

- Verify dead-code claim with one final grep at implementation time.

## Risks & Mitigation

**Risk 1: reflection / DI / dynamic dispatch consumes it**
- *Risk*: hidden consumer via reflection.
- *Mitigation*: scan reflection / DI / config for the method name. None are expected; verify before deletion.

Full change entry: `_docs/04_refactoring/03-code-quality-refactoring/list-of-changes.md` (C27).
