Urgent geometry classics, whose work is Geometry .

How can a famous book be called a famous book if you don't read a book?!

3 Famous Problems of Elementary Geometry by F. Klein (fkiein), translator Shen Yibing 4 Wonderful and Interesting Geometry Author Wells 5 The Story of Geometry Author:

Leonardo Mlodinov 6 Modern Euclidean Geometry Author: R. A. Johnson, translated by Shan Yi 7 Ancient and Modern Mathematical Thought, by Maurice Klein, translated by Zhang Lijing et al. Volume 8 Mathematics, the Loss of Certainty Author: Klein, translated by Li Hongkui 9 Treasures of Mathematics:

Selected Historical Literature Author: Li Wenlin 10 "New Exploration of Geometry" Author: (English) Doxeter, Greitzer (Author) 11 Famous Theorems of Geometry Author:

12 What is Mathematics Author: R. Ke, H. Robin, I. Stewart Revised, Zuo Ping, Chang Yici Translated 13 "Proof and Refutation" by Imre.

Lakatos 14 Mathematics and Conjecture (in two volumes) gPolya, 15 "The Discovery of Mathematics" Author: George Polya, translated by Liu Jinglin et al. 16 "How to Solve Problems" Author:

G. Polya|Translator: Tu Hong Feng Chengtian 17 Mathematics – Its Contents, Methods and Significance (3 Volumes) Former Publishing House USSR Academy Author [Russian] Aleksandrov Translators Sun Xiaoli, Zhao Mengyang Qiu Guangming Yan Shijian 18 The Geometric Properties of Conic Curves --- Popular Mathematics Classics Translation Series Author: UK) a Cockechott 19 The Story of East and West Mathematics Author:

Title: Popular Mathematical Classics Translation Series 20 Proof from the Bible (3rd Edition) Author: (de) Ziegler 21 Calculating the Unexpected (Time Picture from Kepler to Thom) Author:

Xue Mi Subtitle: A Mystery That Puzzled the World's Wise Men for 358 Years 24 100 Famous Mathematical Problems 25 Wisdom and Ingenuity in Mathematics Biography Mathematics Masterpieces 1 "The Love of Numbers" (Biography of Edos) Author: Paul.

Hoffman 2 "My Brain Is Open – The Legend of the Genius Mathematician Paul Edos" by Bruce. Shechter [US] 3 "The Legend of a Female Mathematician" Author: Xu Pinfang 4 "A Mathematician's Confession" Author:

E. T. Bell Subtitle: From Zeno to Poincaré 6 A Brief Dictionary of Biographies of Modern Mathematicians Author: Zhang Dianzhou 7 Biographies of World-Famous Mathematicians (Part I and II) Author: Wu Wenjun 8 Mathematical Elite 9 The Last Alchemist: A Biography of Newton Author: White Excerpt from.

"Nine Chapters of Arithmetic" in the Eastern Han Dynasty

Geometry is the only mathematical work written by the French mathematician Descartes during his lifetime.

Because, PF CB

So, abc= pfh=43°

Because the foci are clear, PH BA

Therefore, PFH is a right-angled triangle of Cryptophyllum officinalis.

i.e., FPH positive dispersion PFH=90°

So, fph 90°-43°=47°

According to the known conditions, the figure can be drawn as if PFBE is a parallelogram, the bright movement is ABC FPE 43°, according to PH BA, PHF HPE 90° is 90°, then FPH is 90°, 43° 47°

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Isn't there anything to prove =-o

First question:

According to the title, the radius of the upper and lower surface of the round table is r=2;The radius of the lower bottom surface of the round table r=5 and the height of the round platform is h, then the height of the round platform, the difference between the two bottom surface radii, and the length of the bus bar of the round table form a right-angled triangle, which is obtained by the Pythagorean theorem

h^2+(5-2)^2=12^2

So h=3 15.

Question 2: Let the bus length of this cone be x, and use the cosine value to be equal by drawing a diagram:

cosa=3/12=5/x

So: x=20cm.