Question

Given the side length a=9 and the angle B=46∘ on the triangle below, find the lengths of b and c and the measure of angle A. Do not round during your calculations, but round your final answers to one decimal place.

Answer 1

well, since all interior angles in a triangle add up to 180°, by definition A = 44°, since B and A are complementary anyway.

`\cos(46^o )=\cfrac{\stackrel{adjacent}{9}}{\underset{hypotenuse}{c}}\implies c=\cfrac{9}{\cos(46^o)}\implies c\approx 13.0 \\\\[-0.35em] ~\dotfill\\\\ \tan(46^o )=\cfrac{\stackrel{opposite}{b}}{\underset{adjacent}{9}}\implies 9\tan(46^o )=b\implies 9.3\approx b`

Make sure your calculator is in Degree mode.