Question

LBN is a 30°-60°-90° triangle and LB = 18 in. Find NB.

Answer 1

In order to calculate the length of NB, let's use the cosine relation of the angle 30°.

The cosine relation is the length of the adjacent side to the angle over the length of the hypotenuse.

So we have:

`\begin{gathered} \cos (30\degree)=(NB)/(BL) \\ \frac{\sqrt[]{3}}{2}=(NB)/(18) \\ 2\cdot NB=18\sqrt[]{3} \\ NB=9\sqrt[]{3} \end{gathered}`