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Category: Geometry

Question-40686

Question Number 40686 by MrW3 last updated on 26/Jul/18 Commented by MrW3 last updated on 26/Jul/18 $${Find}\:{radius}\:{R}\:{of}\:{the}\:{circumsphere}\:{of} \\ $$$${pyramid}. \\ $$$$ \\ $$$${I}\:{got}\:{R}=\frac{\sqrt{\mathrm{3}}{b}^{\mathrm{2}} }{\mathrm{2}\sqrt{\mathrm{3}{b}^{\mathrm{2}} −{a}^{\mathrm{2}}…

Question-40615

Question Number 40615 by behi83417@gmail.com last updated on 24/Jul/18 Commented by behi83417@gmail.com last updated on 24/Jul/18 $${A}\overset{} {{C}B}=\mathrm{90}^{\bullet} ,{A}\overset{} {{C}E}={E}\overset{} {{C}M}={M}\overset{} {{C}B} \\ $$$${AC}={CM}=\mathrm{5},{CB}=\mathrm{12},{MN}\bot{AB}. \\…

Question-40610

Question Number 40610 by ajfour last updated on 24/Jul/18 Answered by MJS last updated on 25/Jul/18 $$\mathrm{easy}\:\mathrm{to}\:\mathrm{understand}\:\mathrm{with}\:\mathrm{4}+\mathrm{1}\:\mathrm{spheres} \\ $$$$\mathrm{let}\:\mathrm{radius}\:\mathrm{of}\:\mathrm{the}\:\mathrm{spheres}\:=\:\mathrm{1} \\ $$$$\mathrm{the}\:\mathrm{angle}\:\mathrm{of}\:\mathrm{the}\:\mathrm{side}\:\mathrm{of}\:\mathrm{the}\:\mathrm{cone}\:\mathrm{is}\:\mathrm{45}° \\ $$$$\mathrm{its}\:\mathrm{radius}=\mathrm{height}\:\mathrm{is}\:\mathrm{1}+\mathrm{2}\sqrt{\mathrm{2}} \\ $$$$\left(\mathrm{cut}\:\mathrm{through}\:\mathrm{the}\:\mathrm{centers}\:\mathrm{of}\:\mathrm{2}\:\mathrm{opposite}\:\mathrm{bottom}\right.…

Question-171677

Question Number 171677 by cherokeesay last updated on 19/Jun/22 Answered by mr W last updated on 19/Jun/22 $${R}=\mathrm{2}{r} \\ $$$${rectangle}\:{a}×{b}\:{with}\:{b}=\mathrm{2}{r} \\ $$$${a}=\sqrt{\left({r}+{R}\right)^{\mathrm{2}} −{r}^{\mathrm{2}} }=\mathrm{2}\sqrt{\mathrm{2}}{r} \\…

Question-40457

Question Number 40457 by behi83417@gmail.com last updated on 22/Jul/18 Answered by MrW3 last updated on 28/Jul/18 $${Q}\mathrm{1}: \\ $$$${the}\:{inscribed}\:{triangle}\:{with}\:{minimal} \\ $$$${perimeter}\:{in}\:{a}\:{given}\:{acute}\:{triangle}\:{is} \\ $$$${that}\:{on}\:{which}\:{links}\:{the}\:{feet}\:{of}\:{the} \\ $$$${altitudes}\:{of}\:{the}\:{given}\:{triangle}.…