VTMO 2020 — Grade 7 — vtmo Question 10

Question 10

Angle xOy $90 ^{\circ}$. Interior rays Oz, Ot satisfy xOz=tOy $30 ^{\circ}$. $K$ lies on Ox with $OK \sqrt{3}$. $KB$ is perpendicular to Oz at $B$; the line through $B$ perpendicular to Ot meets Oy at $D$. Find $OD$.

$\frac{1}{2}$
$\frac{2}{\sqrt{3}}$
$2 \sqrt{3}$
$\frac{3}{2}$
$\frac{\sqrt{3}}{2}$