---
title: "Area of an Irregular Space — ZX81 Program"
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slug: "area-of-an-irregular-space-zx81-program"
url: "http://localhost/article/area-of-an-irregular-space-zx81-program/"
markdown_url: "http://localhost/article/area-of-an-irregular-space-zx81-program.md"
published_at: "2026-03-13T23:53:37+00:00"
modified_at: "2026-03-13T23:53:38+00:00"
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excerpt: "Short ZX81/TS1000 BASIC program that calculates the total area of an irregular polygon by dividing it into triangles and applying Heron's formula to each. The user inputs the number of triangles and the three side lengths of each; the program accumulates the total area. Originally written by John South of Bexhill-on-Sea, Sussex for calculating lawn…"
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  title: "Timelinez"
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volume: "2"
issue: "11"
issues_articles:
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    title: "Timelinez v2 n11"
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pages: "7"
pubdate: "November 1984"
archive_link: false
---

# Area of an Irregular Space — ZX81 Program

Short ZX81/TS1000 BASIC program that calculates the total area of an irregular polygon by dividing it into triangles and applying Heron’s formula to each. The user inputs the number of triangles and the three side lengths of each; the program accumulates the total area. Originally written by John South of Bexhill-on-Sea, Sussex for calculating lawn fertilizer quantities.