Question 9
A rectangle $ABCD$ with $BC=3$ cm and $AB=\sqrt3$ cm is folded along $AC$ so that the point $B$ lands on the point $K$ symmetric to it about $AC$. What is the area, in cm$^2$, of triangle $KDE$, where $E$ is the point on the extension of $BC$ such that $\angle CDE=30^\circ$?
Entry format: use sqrt(3) for the square root of 3, * for multiplication, and / for division; omit units.
Entry format: use sqrt(3) for the square root of 3, * for multiplication, and / for division; omit units.