Answer:
Step-by-step explanation:
Side BW is the height, aka as the side adjacent to the reference angle of 9 degrees. We have the side opposite the reference angle (21) and we are looking for the side adjacent to the reference angle. The trig ratio that we use for this, the one that relates the sides opposite and adjacent, is the tangent ratio, namely:
[tex]tan(9)=\frac{21}{BW}[/tex] and solving for BW:
[tex]BW=\frac{21}{tan(9)}[/tex] so
BW = 132.59
