Using trignometry, $\frac{5}{x}=\sin 30=0.5$

$\Longrightarrow x=10 \mathrm{cm}$

Thus we get $A B=C D=20-10=10 \mathrm{cm}$

since all parts are of same length, thus resistance of each part $R=10 \times 1=10 \Omega$ Equivalent circuit is also shown above.

Equivalence resistance between $\mathrm{B}$ and $\mathrm{E}, R_{B E}=(10+10)\|10=20\| 10$

$\therefore R_{e q}=\frac{20 \times 10}{20+10}=6.7 \Omega$

Equivalent resistance between $\mathrm{A}$ and $\mathrm{D}, R_{A D}=10+6.7+10=26.7 \Omega$