Question 4
a) Show that in a right triangle with an angle of $30^\circ$, the leg opposite to the $30^\circ$-angle has half of the length of the hypotenuse.
b) Inside the triangle $ABC$, with $m(\angle A) = 100^\circ$ and $m(\angle B) = 20^\circ$, we consider the point $D$, such that $m(\angle DAB) = 30^\circ$ and $m(\angle DBA) = 10^\circ$. Determine $m(\angle ACD)$.
b) Inside the triangle $ABC$, with $m(\angle A) = 100^\circ$ and $m(\angle B) = 20^\circ$, we consider the point $D$, such that $m(\angle DAB) = 30^\circ$ and $m(\angle DBA) = 10^\circ$. Determine $m(\angle ACD)$.