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You are not logged in. #1 20140203 21:34:02
Triangles and tangents galoreTriangle ABC, inscribed in a circle, has AB = 15 and BC = 25. A tangent to the circle is drawn at B, and a line through A parallel to this tangent intersects \overline{BC} at D. Find DC. Batman shows Superman his new phone. Batman"Alfred, whats the temperature in London?" Alfred"Just a second, sir." Alfred turns on his iPhone."Siri, whats the temperature in London?" Siri  "Six centigrade." Alfred"Six centigrade sir." Batman"See?" #2 20140203 22:23:05
Re: Triangles and tangents galoreHi thedarktiger; In mathematics, you don't understand things. You just get used to them. I have the result, but I do not yet know how to get it. All physicists, and a good many quite respectable mathematicians are contemptuous about proof. #3 20140204 20:17:46
Re: Triangles and tangents galoreGood morning bobbym, You cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei #5 20140204 22:22:54
Re: Triangles and tangents galoreIt's a strange problem. There are an infinite number of triangles with those measurements. I used Sketchpad to fix AB and then made a circle, centre B, for the locus of C. Then I constructed the rest to find D. As I move C, D moves around a circle of fixed radius, with a radius consistent with your answer for CD, and centre B. But why? Last edited by bob bundy (20140205 00:20:33) You cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei #7 20140205 03:19:33
Re: Triangles and tangents galoreHere is a little video capture of my Geogebra program showing that DC's size remains constant at 16 when BC is pivoted 360° around point B. Last edited by phrontister (20140205 16:29:40) "The good news about computers is that they do what you tell them to do. The bad news is that they do what you tell them to do."  Ted Nelson #9 20140205 06:50:47
Re: Triangles and tangents galoreHi phrontister; In mathematics, you don't understand things. You just get used to them. I have the result, but I do not yet know how to get it. All physicists, and a good many quite respectable mathematicians are contemptuous about proof. #10 20140205 16:49:58
Re: Triangles and tangents galoreThanks, B&B! "The good news about computers is that they do what you tell them to do. The bad news is that they do what you tell them to do."  Ted Nelson #11 20140205 18:53:37
Re: Triangles and tangents galoreThanks Phro, You cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei #12 20140208 13:54:50
Re: Triangles and tangents galoreHmmm. Thanks for the demonstration phronstister! wow, It looks like geoebra is amust Batman shows Superman his new phone. Batman"Alfred, whats the temperature in London?" Alfred"Just a second, sir." Alfred turns on his iPhone."Siri, whats the temperature in London?" Siri  "Six centigrade." Alfred"Six centigrade sir." Batman"See?" #13 20140208 14:23:27
Re: Triangles and tangents galore
In mathematics, you don't understand things. You just get used to them. I have the result, but I do not yet know how to get it. All physicists, and a good many quite respectable mathematicians are contemptuous about proof. #14 20140208 22:40:31
Re: Triangles and tangents galorehi bobbym, You cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei #15 20140208 23:05:30
Re: Triangles and tangents galoreHi; In mathematics, you don't understand things. You just get used to them. I have the result, but I do not yet know how to get it. All physicists, and a good many quite respectable mathematicians are contemptuous about proof. #16 20140208 23:06:09
Re: Triangles and tangents galoreAnd I'll make a claim for the most recent (to date) mention of geogebra on MIF. "The good news about computers is that they do what you tell them to do. The bad news is that they do what you tell them to do."  Ted Nelson #17 20140208 23:07:19
Re: Triangles and tangents galoreThe Alpha and the Omega! In mathematics, you don't understand things. You just get used to them. I have the result, but I do not yet know how to get it. All physicists, and a good many quite respectable mathematicians are contemptuous about proof. #18 20140209 15:30:35
Re: Triangles and tangents galoreso it is Batman shows Superman his new phone. Batman"Alfred, whats the temperature in London?" Alfred"Just a second, sir." Alfred turns on his iPhone."Siri, whats the temperature in London?" Siri  "Six centigrade." Alfred"Six centigrade sir." Batman"See?" 