\u039a\u03b1\u03c4\u03b1\u03c3\u03ba\u03b5\u03c5\u03ae \u03a0\u03b1\u03c1\u03ac\u03bb\u03bb\u03b7\u03bb\u03b7\u03c2 \u03b1\u03c0\u03cc \u03c3\u03b7\u03bc\u03b5\u03af\u03bf \u03b5\u03ba\u03c4\u03cc\u03c2 \u03b5\u03c5\u03b8\u03b5\u03af\u03b5\u03c2 \u03c0\u03c1\u03bf\u03c2 \u03b4\u03bf\u03c3\u03bc\u03ad\u03bd\u03b7 \u03b5\u03c5\u03b8\u03b5\u03af\u03b1 \u0391\u0392 \u03bc\u03b5 \u03b4\u03bf\u03c3\u03bc\u03ad\u03bd\u03bf \u03bc\u03ad\u03c3\u03bf \u03c4\u03bf\u03c5 \u0391\u0392<\/h2>\n\n\n\n![\"\"](\"https:\/\/presswiki.allmath.gr\/wpwiki18\/wp-content\/uploads\/2022\/01\/\u03b5\u03b9\u03ba\u03cc\u03bd\u03b1-23-1024x674.png\")
<\/figure>\n\n\n\n\u0394\u03b5\u03af\u03c4\u03b5 \u03c4\u03b7\u03bd \u03ba\u03b1\u03c4\u03b1\u03c3\u03ba\u03b5\u03c5\u03ae \u03c3\u03c4\u03bf \u03c0\u03b1\u03c1\u03b1\u03ba\u03ac\u03c4\u03c9 gif\u03b1\u03ba\u03b9:<\/p>\n\n\n\n![\"\"](\"https:\/\/presswiki.allmath.gr\/wpwiki18\/wp-content\/uploads\/2022\/01\/steinerconstr1-2022-01-04-22-23-1.gif\")
<\/figure>\n\n\n\nhttps:\/\/www.geogebra.org\/geometry\/mxvcjzuw?embed<\/a><\/p>\n\n\n\n\u039a\u03b1\u03c4\u03b1\u03c3\u03ba\u03b5\u03c5\u03ae \u03ba\u03ac\u03b8\u03b5\u03c4\u03b7\u03c2 \u03c0\u03c1\u03bf\u03c2 \u03b5\u03c5\u03b8\u03b5\u03af\u03b1 \u03b1\u03c0\u03cc \u03b4\u03bf\u03c3\u03bc\u03ad\u03bd\u03bf \u03c3\u03b7\u03bc\u03b5\u03af\u03bf.<\/h2>\n\n\n\n
https:\/\/www.geogebra.org\/classic\/zzquanan<\/a><\/p>\n\n\n\n![\"\"](\"https:\/\/presswiki.allmath.gr\/wpwiki18\/wp-content\/uploads\/2022\/01\/\u03b5\u03b9\u03ba\u03cc\u03bd\u03b1-25-1024x483.png\")
<\/figure>\n\n\n\n<\/p>\n\n\n\n
<\/p>\n\n\n\n
\u039a\u03b1\u03c4\u03b1\u03c3\u03ba\u03b5\u03c5\u03ae steiner \u03b5\u03c5\u03b8\u03c5\u03b3\u03c1\u03ac\u03bc\u03bc\u03bf\u03c5 \u03c4\u03bc\u03ae\u03bc\u03b1\u03c4\u03bf\u03c2 \u03c3\u03b5 \u03b4\u03bf\u03c3\u03bc\u03ad\u03bd\u03b7 \u03b5\u03c5\u03b8\u03b5\u03af\u03b1, \u03bc\u03b5 \u03c4\u03bf \u03bc\u03ad\u03c3\u03bf \u03c4\u03bf\u03c5<\/h2>\n\n\n\n
https:\/\/www.geogebra.org\/classic\/becnhq6t<\/a><\/p>\n\n\n\n\u039a\u03b1\u03c4\u03b1\u03c3\u03ba\u03b5\u03c5\u03ae Steiner \u03c0\u03b1\u03c1\u03ac\u03bb\u03bb\u03b7\u03bb\u03b7\u03c2 \u03b1\u03c0\u03cc \u03b4\u03bf\u03c3\u03bc\u03ad\u03bd\u03bf \u03c3\u03b7\u03bc\u03b5\u03af\u03bf \u03c3\u03b5 \u03b4\u03b9\u03ac\u03bc\u03b5\u03c4\u03c1\u03bf \u03b4\u03bf\u03c3\u03bc\u03ad\u03bd\u03bf\u03c5 \u03ba\u03cd\u03ba\u03bb\u03bf\u03c5.<\/h2>\n\n\n\n
https:\/\/www.geogebra.org\/classic\/mftdyqv3<\/a><\/p>\n\n\n\n![\"\"](\"https:\/\/presswiki.allmath.gr\/wpwiki18\/wp-content\/uploads\/2022\/01\/\u03b5\u03b9\u03ba\u03cc\u03bd\u03b1-26-1024x537.png\")
<\/figure>\n\n\n\n<\/p>\n\n\n\n
<\/p>\n\n\n\n
The Poncelet-Steiner theorem says<\/p>\n\n\n\n
Everything you can construct with a straightedge and a compass you can construct by the straightedge alone, provided you are given a circle and its center.<\/em><\/p>\n\n\n\nMotivated by Mascheroni\u2019s result \u2191 J.V.Poncelet conjectured this results in 1812\ufffd\ufffd[1]\ufffd\ufffdand it was proved by J.Steiner [2]\ufffd\ufffdin 1833.<\/p>\n\n\n\n
It can be shown that the constructions cannot be done by straightedge alone [3] . By the straightedge alone only the so called linear constructions can be done. For instance, using the straightedge alone, without a circle given, is not sufficient to construct square roots. Even simpler constructions as to half a straight line segment are impossible by the straightedge alone. Another example is the result known as Steiner\u2019s theorem:<\/p>\n\n\n\n
Steiner\u2019s Theorem:<\/strong> It is impossible to find the center of a given circle with the straightedge alone.<\/em><\/p>\n\n\n\nThe basic idea of the following proof goes back to Hilbert. If such a construction would be possible, then it would be preserved by projective transformations.\ufffd\ufffdThis due to the basic properties of projective transformation which preserve lines, objects constructible by the straightedge. On the other hand, the circle as a conic section is transformed to a conic section in general.\ufffd\ufffdEven worse, the conjugate diameters 1<\/sup> of a conic section pre-image may not be transformed to the conjugate diameters of the image. Consequently, the center of circle is not projected to the center of the image.<\/p>\n\n\n\n\u03a0\u03b7\u03b3\u03ae: http:\/\/www.cs.cas.cz\/portal\/AlgoMath\/Geometry\/PlaneGeometry\/GeometricConstructions\/PonceletSteinerTheorem.htm<\/a><\/p>\n\n\n\n\u0386\u03c1\u03b8\u03c1\u03bf Poncelet-Steiner<\/h2>\n\n\n\n33-Poncelet-Steiner-Theorem<\/a>\u039b\u03ae\u03c8\u03b7<\/a><\/div>\n\n\n33-Poncelet-Steiner-Theorem\u0395\u03c0\u03b9\u03c0\u03bb\u03ad\u03bf\u03bd \u03c0\u03b7\u03b3\u03ad\u03c2<\/h2>\n\n\n\n
http:\/\/www.cs.cas.cz\/portal\/contents.htm<\/a><\/p>\n\n\n\nGeogebra: https:\/\/www.geogebra.org\/m\/e4hHkzpa<\/a><\/p>\n\n\n\n<\/p>\n","protected":false},"excerpt":{"rendered":"
\u0393\u03b5\u03c9\u03bc\u03b5\u03c4\u03c1\u03b9\u03ba\u03ad\u03c2 \u03ba\u03b1\u03c4\u03b1\u03c3\u03ba\u03b5\u03c5\u03ad\u03c2 \u03bc\u03b5 \u03ba\u03b1\u03bd\u03cc\u03bd\u03b1 \u03ba\u03b1\u03b9 \u00ab\u03c3\u03ba\u03bf\u03c5\u03c1\u03b9\u03b1\u03c3\u03bc\u03ad\u03bd\u03bf\u00bb \u03b4\u03b9\u03b1\u03b2\u03ae\u03c4\u03b7 ! https:\/\/en.wikipedia.org\/wiki\/Poncelet%E2%80%93Steiner_theorem \u039a\u03b1\u03c4\u03b1\u03c3\u03ba\u03b5\u03c5\u03ae \u03a0\u03b1\u03c1\u03ac\u03bb\u03bb\u03b7\u03bb\u03b7\u03c2 \u03b1\u03c0\u03cc \u03c3\u03b7\u03bc\u03b5\u03af\u03bf \u03b5\u03ba\u03c4\u03cc\u03c2 \u03b5\u03c5\u03b8\u03b5\u03af\u03b5\u03c2 \u03c0\u03c1\u03bf\u03c2 \u03b4\u03bf\u03c3\u03bc\u03ad\u03bd\u03b7 \u03b5\u03c5\u03b8\u03b5\u03af\u03b1 \u0391\u0392 \u03bc\u03b5 \u03b4\u03bf\u03c3\u03bc\u03ad\u03bd\u03bf \u03bc\u03ad\u03c3\u03bf \u03c4\u03bf\u03c5 \u0391\u0392 \u0394\u03b5\u03af\u03c4\u03b5 \u03c4\u03b7\u03bd \u03ba\u03b1\u03c4\u03b1\u03c3\u03ba\u03b5\u03c5\u03ae \u03c3\u03c4\u03bf \u03c0\u03b1\u03c1\u03b1\u03ba\u03ac\u03c4\u03c9 gif\u03b1\u03ba\u03b9: https:\/\/www.geogebra.org\/geometry\/mxvcjzuw?embed \u039a\u03b1\u03c4\u03b1\u03c3\u03ba\u03b5\u03c5\u03ae \u03ba\u03ac\u03b8\u03b5\u03c4\u03b7\u03c2 \u03c0\u03c1\u03bf\u03c2 \u03b5\u03c5\u03b8\u03b5\u03af\u03b1 \u03b1\u03c0\u03cc \u03b4\u03bf\u03c3\u03bc\u03ad\u03bd\u03bf \u03c3\u03b7\u03bc\u03b5\u03af\u03bf. https:\/\/www.geogebra.org\/classic\/zzquanan \u039a\u03b1\u03c4\u03b1\u03c3\u03ba\u03b5\u03c5\u03ae steiner \u03b5\u03c5\u03b8\u03c5\u03b3\u03c1\u03ac\u03bc\u03bc\u03bf\u03c5 \u03c4\u03bc\u03ae\u03bc\u03b1\u03c4\u03bf\u03c2 \u03c3\u03b5 \u03b4\u03bf\u03c3\u03bc\u03ad\u03bd\u03b7 \u03b5\u03c5\u03b8\u03b5\u03af\u03b1, \u03bc\u03b5 \u03c4\u03bf \u03bc\u03ad\u03c3\u03bf \u03c4\u03bf\u03c5 https:\/\/www.geogebra.org\/classic\/becnhq6t \u039a\u03b1\u03c4\u03b1\u03c3\u03ba\u03b5\u03c5\u03ae Steiner \u03c0\u03b1\u03c1\u03ac\u03bb\u03bb\u03b7\u03bb\u03b7\u03c2 \u03b1\u03c0\u03cc … \u0394\u03b9\u03b1\u03b2\u03ac\u03c3\u03c4\u03b5 \u03c0\u03b5\u03c1\u03b9\u03c3\u03c3\u03cc\u03c4\u03b5\u03c1\u03b1 “\u0398\u03b5\u03ce\u03c1\u03b7\u03bc\u03b1 Poncelet-Steiner”<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[36,11,13,3,16],"tags":[720,732,443,731],"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/presswiki.allmath.gr\/wpwiki18\/wp-json\/wp\/v2\/posts\/5805"}],"collection":[{"href":"https:\/\/presswiki.allmath.gr\/wpwiki18\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/presswiki.allmath.gr\/wpwiki18\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/presswiki.allmath.gr\/wpwiki18\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/presswiki.allmath.gr\/wpwiki18\/wp-json\/wp\/v2\/comments?post=5805"}],"version-history":[{"count":8,"href":"https:\/\/presswiki.allmath.gr\/wpwiki18\/wp-json\/wp\/v2\/posts\/5805\/revisions"}],"predecessor-version":[{"id":5824,"href":"https:\/\/presswiki.allmath.gr\/wpwiki18\/wp-json\/wp\/v2\/posts\/5805\/revisions\/5824"}],"wp:attachment":[{"href":"https:\/\/presswiki.allmath.gr\/wpwiki18\/wp-json\/wp\/v2\/media?parent=5805"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/presswiki.allmath.gr\/wpwiki18\/wp-json\/wp\/v2\/categories?post=5805"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/presswiki.allmath.gr\/wpwiki18\/wp-json\/wp\/v2\/tags?post=5805"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
<\/figure>\n\n\n\n\u0394\u03b5\u03af\u03c4\u03b5 \u03c4\u03b7\u03bd \u03ba\u03b1\u03c4\u03b1\u03c3\u03ba\u03b5\u03c5\u03ae \u03c3\u03c4\u03bf \u03c0\u03b1\u03c1\u03b1\u03ba\u03ac\u03c4\u03c9 gif\u03b1\u03ba\u03b9:<\/p>\n\n\n\n https:\/\/www.geogebra.org\/geometry\/mxvcjzuw?embed<\/a><\/p>\n\n\n\n https:\/\/www.geogebra.org\/classic\/zzquanan<\/a><\/p>\n\n\n\n <\/p>\n\n\n\n <\/p>\n\n\n\n https:\/\/www.geogebra.org\/classic\/becnhq6t<\/a><\/p>\n\n\n\n https:\/\/www.geogebra.org\/classic\/mftdyqv3<\/a><\/p>\n\n\n\n <\/p>\n\n\n\n <\/p>\n\n\n\n The Poncelet-Steiner theorem says<\/p>\n\n\n\n Everything you can construct with a straightedge and a compass you can construct by the straightedge alone, provided you are given a circle and its center.<\/em><\/p>\n\n\n\n Motivated by Mascheroni\u2019s result \u2191 J.V.Poncelet conjectured this results in 1812\ufffd\ufffd[1]\ufffd\ufffdand it was proved by J.Steiner [2]\ufffd\ufffdin 1833.<\/p>\n\n\n\n It can be shown that the constructions cannot be done by straightedge alone [3] . By the straightedge alone only the so called linear constructions can be done. For instance, using the straightedge alone, without a circle given, is not sufficient to construct square roots. Even simpler constructions as to half a straight line segment are impossible by the straightedge alone. Another example is the result known as Steiner\u2019s theorem:<\/p>\n\n\n\n Steiner\u2019s Theorem:<\/strong> It is impossible to find the center of a given circle with the straightedge alone.<\/em><\/p>\n\n\n\n The basic idea of the following proof goes back to Hilbert. If such a construction would be possible, then it would be preserved by projective transformations.\ufffd\ufffdThis due to the basic properties of projective transformation which preserve lines, objects constructible by the straightedge. On the other hand, the circle as a conic section is transformed to a conic section in general.\ufffd\ufffdEven worse, the conjugate diameters 1<\/sup> of a conic section pre-image may not be transformed to the conjugate diameters of the image. Consequently, the center of circle is not projected to the center of the image.<\/p>\n\n\n\n \u03a0\u03b7\u03b3\u03ae: http:\/\/www.cs.cas.cz\/portal\/AlgoMath\/Geometry\/PlaneGeometry\/GeometricConstructions\/PonceletSteinerTheorem.htm<\/a><\/p>\n\n\n\n http:\/\/www.cs.cas.cz\/portal\/contents.htm<\/a><\/p>\n\n\n\n Geogebra: https:\/\/www.geogebra.org\/m\/e4hHkzpa<\/a><\/p>\n\n\n\n <\/p>\n","protected":false},"excerpt":{"rendered":" \u0393\u03b5\u03c9\u03bc\u03b5\u03c4\u03c1\u03b9\u03ba\u03ad\u03c2 \u03ba\u03b1\u03c4\u03b1\u03c3\u03ba\u03b5\u03c5\u03ad\u03c2 \u03bc\u03b5 \u03ba\u03b1\u03bd\u03cc\u03bd\u03b1 \u03ba\u03b1\u03b9 \u00ab\u03c3\u03ba\u03bf\u03c5\u03c1\u03b9\u03b1\u03c3\u03bc\u03ad\u03bd\u03bf\u00bb \u03b4\u03b9\u03b1\u03b2\u03ae\u03c4\u03b7 ! https:\/\/en.wikipedia.org\/wiki\/Poncelet%E2%80%93Steiner_theorem \u039a\u03b1\u03c4\u03b1\u03c3\u03ba\u03b5\u03c5\u03ae \u03a0\u03b1\u03c1\u03ac\u03bb\u03bb\u03b7\u03bb\u03b7\u03c2 \u03b1\u03c0\u03cc \u03c3\u03b7\u03bc\u03b5\u03af\u03bf \u03b5\u03ba\u03c4\u03cc\u03c2 \u03b5\u03c5\u03b8\u03b5\u03af\u03b5\u03c2 \u03c0\u03c1\u03bf\u03c2 \u03b4\u03bf\u03c3\u03bc\u03ad\u03bd\u03b7 \u03b5\u03c5\u03b8\u03b5\u03af\u03b1 \u0391\u0392 \u03bc\u03b5 \u03b4\u03bf\u03c3\u03bc\u03ad\u03bd\u03bf \u03bc\u03ad\u03c3\u03bf \u03c4\u03bf\u03c5 \u0391\u0392 \u0394\u03b5\u03af\u03c4\u03b5 \u03c4\u03b7\u03bd \u03ba\u03b1\u03c4\u03b1\u03c3\u03ba\u03b5\u03c5\u03ae \u03c3\u03c4\u03bf \u03c0\u03b1\u03c1\u03b1\u03ba\u03ac\u03c4\u03c9 gif\u03b1\u03ba\u03b9: https:\/\/www.geogebra.org\/geometry\/mxvcjzuw?embed \u039a\u03b1\u03c4\u03b1\u03c3\u03ba\u03b5\u03c5\u03ae \u03ba\u03ac\u03b8\u03b5\u03c4\u03b7\u03c2 \u03c0\u03c1\u03bf\u03c2 \u03b5\u03c5\u03b8\u03b5\u03af\u03b1 \u03b1\u03c0\u03cc \u03b4\u03bf\u03c3\u03bc\u03ad\u03bd\u03bf \u03c3\u03b7\u03bc\u03b5\u03af\u03bf. https:\/\/www.geogebra.org\/classic\/zzquanan \u039a\u03b1\u03c4\u03b1\u03c3\u03ba\u03b5\u03c5\u03ae steiner \u03b5\u03c5\u03b8\u03c5\u03b3\u03c1\u03ac\u03bc\u03bc\u03bf\u03c5 \u03c4\u03bc\u03ae\u03bc\u03b1\u03c4\u03bf\u03c2 \u03c3\u03b5 \u03b4\u03bf\u03c3\u03bc\u03ad\u03bd\u03b7 \u03b5\u03c5\u03b8\u03b5\u03af\u03b1, \u03bc\u03b5 \u03c4\u03bf \u03bc\u03ad\u03c3\u03bf \u03c4\u03bf\u03c5 https:\/\/www.geogebra.org\/classic\/becnhq6t \u039a\u03b1\u03c4\u03b1\u03c3\u03ba\u03b5\u03c5\u03ae Steiner \u03c0\u03b1\u03c1\u03ac\u03bb\u03bb\u03b7\u03bb\u03b7\u03c2 \u03b1\u03c0\u03cc … \u0394\u03b9\u03b1\u03b2\u03ac\u03c3\u03c4\u03b5 \u03c0\u03b5\u03c1\u03b9\u03c3\u03c3\u03cc\u03c4\u03b5\u03c1\u03b1 “\u0398\u03b5\u03ce\u03c1\u03b7\u03bc\u03b1 Poncelet-Steiner”<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[36,11,13,3,16],"tags":[720,732,443,731],"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/presswiki.allmath.gr\/wpwiki18\/wp-json\/wp\/v2\/posts\/5805"}],"collection":[{"href":"https:\/\/presswiki.allmath.gr\/wpwiki18\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/presswiki.allmath.gr\/wpwiki18\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/presswiki.allmath.gr\/wpwiki18\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/presswiki.allmath.gr\/wpwiki18\/wp-json\/wp\/v2\/comments?post=5805"}],"version-history":[{"count":8,"href":"https:\/\/presswiki.allmath.gr\/wpwiki18\/wp-json\/wp\/v2\/posts\/5805\/revisions"}],"predecessor-version":[{"id":5824,"href":"https:\/\/presswiki.allmath.gr\/wpwiki18\/wp-json\/wp\/v2\/posts\/5805\/revisions\/5824"}],"wp:attachment":[{"href":"https:\/\/presswiki.allmath.gr\/wpwiki18\/wp-json\/wp\/v2\/media?parent=5805"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/presswiki.allmath.gr\/wpwiki18\/wp-json\/wp\/v2\/categories?post=5805"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/presswiki.allmath.gr\/wpwiki18\/wp-json\/wp\/v2\/tags?post=5805"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}<\/figure>\n\n\n\n\u039a\u03b1\u03c4\u03b1\u03c3\u03ba\u03b5\u03c5\u03ae \u03ba\u03ac\u03b8\u03b5\u03c4\u03b7\u03c2 \u03c0\u03c1\u03bf\u03c2 \u03b5\u03c5\u03b8\u03b5\u03af\u03b1 \u03b1\u03c0\u03cc \u03b4\u03bf\u03c3\u03bc\u03ad\u03bd\u03bf \u03c3\u03b7\u03bc\u03b5\u03af\u03bf.<\/h2>\n\n\n\n
<\/figure>\n\n\n\n\u039a\u03b1\u03c4\u03b1\u03c3\u03ba\u03b5\u03c5\u03ae steiner \u03b5\u03c5\u03b8\u03c5\u03b3\u03c1\u03ac\u03bc\u03bc\u03bf\u03c5 \u03c4\u03bc\u03ae\u03bc\u03b1\u03c4\u03bf\u03c2 \u03c3\u03b5 \u03b4\u03bf\u03c3\u03bc\u03ad\u03bd\u03b7 \u03b5\u03c5\u03b8\u03b5\u03af\u03b1, \u03bc\u03b5 \u03c4\u03bf \u03bc\u03ad\u03c3\u03bf \u03c4\u03bf\u03c5<\/h2>\n\n\n\n
\u039a\u03b1\u03c4\u03b1\u03c3\u03ba\u03b5\u03c5\u03ae Steiner \u03c0\u03b1\u03c1\u03ac\u03bb\u03bb\u03b7\u03bb\u03b7\u03c2 \u03b1\u03c0\u03cc \u03b4\u03bf\u03c3\u03bc\u03ad\u03bd\u03bf \u03c3\u03b7\u03bc\u03b5\u03af\u03bf \u03c3\u03b5 \u03b4\u03b9\u03ac\u03bc\u03b5\u03c4\u03c1\u03bf \u03b4\u03bf\u03c3\u03bc\u03ad\u03bd\u03bf\u03c5 \u03ba\u03cd\u03ba\u03bb\u03bf\u03c5.<\/h2>\n\n\n\n
<\/figure>\n\n\n\n\u0386\u03c1\u03b8\u03c1\u03bf Poncelet-Steiner<\/h2>\n\n\n\n
\u0395\u03c0\u03b9\u03c0\u03bb\u03ad\u03bf\u03bd \u03c0\u03b7\u03b3\u03ad\u03c2<\/h2>\n\n\n\n