Question

Please help! check attachment. This is grade 11 trigonometry

Answer 1

$~~~~~~~\tan \theta = \dfrac{\text{Perpendicular}}{\text{Base}}\\\\\\\implies \tan B = \dfrac{AC}{BC}\\\\\\\implies \tan 40^{\circ} = \dfrac{10}{a}\\\\\\\implies a = \dfrac{10}{\tan 40^{\circ}}\\\\\\\implies a= 11.9~ m$