Question Number 161105 by Abdulazizov last updated on 12/Dec/21
Commented by Ari last updated on 12/Dec/21
AD=BC?!
Answered by mr W last updated on 12/Dec/21
Commented by mr W last updated on 12/Dec/21
$${let}\:\angle{DCB}=\theta \\ $$$$\Rightarrow\angle{DAB}=\angle{CBA}=\pi−\theta \\ $$$${AB}={EB}=\mathrm{4} \\ $$$${DA}={DE}\:\left({given}\right) \\ $$$$\Rightarrow\angle{DEB}=\angle{DAB}=\pi−\theta \\ $$$$\angle{DEC}=\pi−\angle{DEB}=\pi−\left(\pi−\theta\right)=\theta=\angle{DCE} \\ $$$$\Rightarrow{DC}={DE} \\ $$$$\:\:\:\:\:\:\:\:\:\:\:\:\:={DA}={CB}=\mathrm{5}+\mathrm{4}=\mathrm{9} \\ $$$$\Rightarrow{x}=\mathrm{9} \\ $$
Commented by Tawa11 last updated on 12/Dec/21
$$\mathrm{Great}\:\mathrm{sir}. \\ $$