Question Number 176820 by Ar Brandon last updated on 27/Sep/22
Commented by mr W last updated on 27/Sep/22
Commented by som(math1967) last updated on 27/Sep/22
$${i}\:{also}\:{misread} \\ $$$${x}=\frac{\mathrm{180}−\mathrm{20}}{\mathrm{2}}=\mathrm{80} \\ $$$${thanks}\:{Rashid}\:{sir}\:{for}\:{correction} \\ $$
Commented by mr W last updated on 27/Sep/22
$${i}\:{misread}\:{as}\:{octagon}. \\ $$$${in}\:{case}\:{of}\:{octadecagon},\:{the}\:{right}\:{answer} \\ $$$${is}\:{indeed}\:\mathrm{80}°. \\ $$$$\frac{\mathrm{360}}{\mathrm{9}}−\frac{\mathrm{360}}{\mathrm{18}}=\mathrm{20} \\ $$$${x}=\frac{\mathrm{180}−\mathrm{20}}{\mathrm{2}}=\mathrm{80}° \\ $$$${Ar}\:{Brandon}\:{sir}: \\ $$$${sorry}\:{for}\:{my}\:{mistake}! \\ $$
Commented by cortano1 last updated on 27/Sep/22
$$\mathrm{what}\:\mathrm{the}\:\mathrm{formula}\:\mathrm{for}\:\mathrm{interior}\:\mathrm{angle}\:\mathrm{sir}\:\mathrm{W}? \\ $$
Commented by Ar Brandon last updated on 27/Sep/22
Got it! Thanks!
Commented by Ar Brandon last updated on 27/Sep/22
$$\mathrm{Thanks}\:\mathrm{so}\:\mathrm{very}\:\mathrm{much}! \\ $$
Commented by Rasheed.Sindhi last updated on 27/Sep/22
$$\mathcal{B}{ut}\:\boldsymbol{{sir}}\:{in}\:{the}\:{question}\:\boldsymbol{{octadecagon}} \\ $$$${is}\:{mentioned}\:{instead}\:{of}\:\boldsymbol{{octagon}}? \\ $$
Commented by mr W last updated on 27/Sep/22
Commented by mr W last updated on 27/Sep/22
$$\mathrm{2}{x}+\mathrm{5}°=\mathrm{180}° \\ $$$$\Rightarrow{x}=\frac{\mathrm{180}−\mathrm{5}}{\mathrm{2}}=\mathrm{87}.\mathrm{5}° \\ $$
Commented by mr W last updated on 27/Sep/22
Commented by mr W last updated on 27/Sep/22
Commented by Ar Brandon last updated on 27/Sep/22
$$\mathrm{Please}\:\mathrm{Sir},\:\mathrm{what}\:\mathrm{do}\:\frac{\mathrm{360}}{\mathrm{8}}−\frac{\mathrm{360}}{\mathrm{9}}\:\mathrm{mean}\:? \\ $$$$\mathrm{Is}\:\mathrm{it}\:\mathrm{a}\:\mathrm{theory}? \\ $$
Commented by Ar Brandon last updated on 27/Sep/22
OK sir
Commented by mr W last updated on 27/Sep/22
$${interior}\:{angle}\:=\mathrm{180}°−{exterior}\:{angle} \\ $$$$\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:=\mathrm{180}°−\frac{\mathrm{360}°}{{n}} \\ $$
Commented by Ar Brandon last updated on 27/Sep/22
Thank you Sir
Commented by Ar Brandon last updated on 27/Sep/22
Right answer is 80° , sir
Commented by mr W last updated on 27/Sep/22
$$\mathrm{87}.\mathrm{5}°\:{is}\:{correct}! \\ $$$$\frac{\mathrm{360}}{\mathrm{8}}−\frac{\mathrm{360}}{\mathrm{9}}=\mathrm{5} \\ $$$${x}=\frac{\mathrm{180}−\mathrm{5}}{\mathrm{2}}=\mathrm{87}.\mathrm{5}° \\ $$
Commented by Ar Brandon last updated on 27/Sep/22
OK sir. If you both agree on that. Thanks!
Commented by mr W last updated on 27/Sep/22
$${this}\:{is}\:{not}\:{an}\:{opinion},\:{but}\:{a}\:{fact}! \\ $$$${it}\:{is}\:{proved}\:{that}\:{x}\:{is}\:{and}\:{can}\:{only}\:{be} \\ $$$$\mathrm{87}.\mathrm{5}°. \\ $$
Commented by Tawa11 last updated on 28/Sep/22
$$\mathrm{Great}\:\mathrm{sirs}. \\ $$