{"book":"adl0946","page":215,"text":"۲۰۸\nرا امتداد داده و زوایای خارجی را نمره ۱ و ۲ و ۳ و ۴ و ۵ و\n۶ می گزاریم حال میخواهیم مجموع این زوایا را معلوم کنیم\nهمان قاعده که دریافتن مجموع زوایای مثلث بکار بردیم\nدرین جا هم بکار می بریم - یعنی نقطه ه ماننده فرض کرده از\nآن نقطه دونیم خط ه ج و ه د را بموازات ج ب و ج د در یک\nجهت رسم می کنیم زاویه حاصله مساوی با زاویه ۱ است برای\nساختن زاویه مساوی بازاویه ۲ نیم خط ه در دست است فقط از نقطه ه نیم\nخطی بموازات د ل در همان جهت رسم مینمائیم و بهمین طریق هم خط های دیگر را\nرسم میکنیم تا ه ج و ه د وه ل و ه م و ه ن و ه ا موازی با\nا ب و ج د و د ل و ل م و م ن و ن ا بدست می آیند\nپس معلوم می شود که تمام زوایای خارجی کثیرالاضلاع\nبدور نقطه ه جمع شده جای خالی باقی نمانده است از\nروی شکل قضیه ذیل را بیان می کنیم -\nقضیه - هرگاه اضلاع کثیرالاضلاعی را در یک\nجهت امتداد دهیم مجموع زوایای خارجی حاصله","chars":787,"image":"https://storage.googleapis.com/adl-page-images/adl0946/00215.jpg","first_page":1,"last_page":327,"title":"Handasah-ʼi musaṭṭaḥah barā-yi ṣinf-i haftum-i makātib-i rushdīyah, bi-qarār-i prūghram-i Vizārat-i Jalīlah-ʼi Muʻārif-i Afghānistān هندسۀ مسطحه :هندسۀ مسطحه","permalink":"https://afghanpress.org/book/adl0946/215","canvas":"https://afghanpress.org/iiif/adl0946/canvas/215","source":"https://afghanistandl.nyu.edu/books/adl0946/","source_pdf":"https://afghanistandl.nyu.edu/pdf/adl0946_download.pdf","rights":{"image":{"statement":"Public domain. NYU states: \"All works presented on this website are, unless otherwise indicated, in the public domain. The images available on this website may be freely reproduced, distributed and transmitted by anyone for any purpose, commercial or non-commercial.\"","uri":"http://rightsstatements.org/vocab/NoC-US/1.0/","holder":"New York University Libraries","source":"https://afghanistandl.nyu.edu/about.html","delivery":"Images are served from a copy mirrored by this project, not from NYU's servers, under the reproduction terms above.","endorsement":"This is an independent project. It is not affiliated with, endorsed by, or reviewed by New York University."},"text":{"statement":"Machine-generated transcription, dedicated to the public domain under CC0 1.0. No warranty of accuracy: see the provenance block on every page.","uri":"https://creativecommons.org/publicdomain/zero/1.0/","holder":"Steps Ventures"}},"provenance":{"text_produced_by":"gemini-3.1-pro-preview","thinking_level":"low","read_completed":"2026-08-09","per_page_confidence":null,"per_page_confidence_note":"Not recorded during the corpus run. No calibrated per-page score exists, and none is estimated here.","human_reviewed":false,"accuracy_context":"Roughly two thirds of characters agree with a modern printed edition of the same text. Much of the disagreement is editorial, not misreading. Treat the transcription as a finding aid and read the page image before quoting.","primary_source":"The page image. The text is an index into it."}}