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4-33-7-4-24-6-5-4-a-9-b-18-c-27-d-36-

Question Number 201041 by hardmath last updated on 28/Nov/23 $$\mathrm{4}\left(\mathrm{33}\right)\mathrm{7} \\ $$$$\mathrm{4}\left(\mathrm{24}\right)\mathrm{6} \\ $$$$\mathrm{5}\left(\:?\:\right)\mathrm{4} \\ $$$$ \\ $$$$\left.{a}\left.\right)\left.\mathrm{9}\left.\:\:\:\:\:{b}\right)\mathrm{18}\:\:\:\:\:{c}\right)\mathrm{27}\:\:\:\:\:{d}\right)\mathrm{36} \\ $$ Answered by Frix last updated…

Question-201037

Question Number 201037 by mr W last updated on 28/Nov/23 Commented by mr W last updated on 28/Nov/23 $${a}\:{triangle}\:{has}\:{sides}\:{a},\:{b},\:{c}.\:{find}\:{the} \\ $$$${fraction}\:{of}\:{its}\:{area}\:{covered}\:{by}\:{all} \\ $$$$\left({infinite}\right)\:{inscribed}\:{circles}\:{as}\:{shown}. \\ $$…

Question-201033

Question Number 201033 by Mingma last updated on 28/Nov/23 Answered by Frix last updated on 28/Nov/23 $$\mathrm{sin}\:\frac{\pi}{\mathrm{14}}\:\mathrm{sin}\:\frac{\mathrm{3}\pi}{\mathrm{14}}\:\mathrm{sin}\:\frac{\mathrm{9}\pi}{\mathrm{14}}\:={x} \\ $$$$\mathrm{0}<{x}<\mathrm{1} \\ $$$$\mathrm{Using}\:\mathrm{trigonometric}\:\mathrm{formulas}\:\Rightarrow \\ $$$$\frac{\mathrm{1}}{\mathrm{4}}\left(\mathrm{1}−\mathrm{cos}\:\frac{\pi}{\mathrm{7}}\:+\mathrm{sin}\:\frac{\mathrm{3}\pi}{\mathrm{14}}\:−\mathrm{sin}\:\frac{\pi}{\mathrm{14}}\right)={x}\:\bigstar \\ $$$$\mathrm{cos}\:\frac{\pi}{\mathrm{7}}\:−\mathrm{sin}\:\frac{\mathrm{3}\pi}{\mathrm{14}}\:+\mathrm{sin}\:\frac{\pi}{\mathrm{14}}\:=\mathrm{1}−\mathrm{4}{x}…