{"title":"a2=b2+cd,勾股公式的一个推广","authors":"F. Laudano","doi":"10.1080/00029890.2023.2231798","DOIUrl":null,"url":null,"abstract":"Henry Perigal was an amateur mathematician and a member of the London Mathematical Society from 1868 to 1897. He is perhaps best known for his proof of the Pythagorean theorem by dissection and transposition [3, 4]. Here we extend the Perigal method to give a new proof for a result that has been called the extended Pythagorean formula [1, 2]. Consider triangle ABC, with BC ≥ AB. Let D be the point on AC such that BD = AB and E the point on the extension of BA where AE = DC. The triangles EAA′ and CDB are congruent, EA′ = CB, and A EA′ = D CB.","PeriodicalId":7761,"journal":{"name":"American Mathematical Monthly","volume":null,"pages":null},"PeriodicalIF":0.4000,"publicationDate":"2023-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"a2=b2+cd, an Extended Pythagorean Formula\",\"authors\":\"F. Laudano\",\"doi\":\"10.1080/00029890.2023.2231798\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"Henry Perigal was an amateur mathematician and a member of the London Mathematical Society from 1868 to 1897. He is perhaps best known for his proof of the Pythagorean theorem by dissection and transposition [3, 4]. Here we extend the Perigal method to give a new proof for a result that has been called the extended Pythagorean formula [1, 2]. Consider triangle ABC, with BC ≥ AB. Let D be the point on AC such that BD = AB and E the point on the extension of BA where AE = DC. The triangles EAA′ and CDB are congruent, EA′ = CB, and A EA′ = D CB.\",\"PeriodicalId\":7761,\"journal\":{\"name\":\"American Mathematical Monthly\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":0.4000,\"publicationDate\":\"2023-07-17\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"American Mathematical Monthly\",\"FirstCategoryId\":\"100\",\"ListUrlMain\":\"https://doi.org/10.1080/00029890.2023.2231798\",\"RegionNum\":4,\"RegionCategory\":\"数学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q4\",\"JCRName\":\"MATHEMATICS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"American Mathematical Monthly","FirstCategoryId":"100","ListUrlMain":"https://doi.org/10.1080/00029890.2023.2231798","RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"MATHEMATICS","Score":null,"Total":0}
Henry Perigal was an amateur mathematician and a member of the London Mathematical Society from 1868 to 1897. He is perhaps best known for his proof of the Pythagorean theorem by dissection and transposition [3, 4]. Here we extend the Perigal method to give a new proof for a result that has been called the extended Pythagorean formula [1, 2]. Consider triangle ABC, with BC ≥ AB. Let D be the point on AC such that BD = AB and E the point on the extension of BA where AE = DC. The triangles EAA′ and CDB are congruent, EA′ = CB, and A EA′ = D CB.
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