In ΔLMN, the measure of ∠N=90°, the measure of ∠M=17°, and MN = 20 feet. Find the length of LM to the nearest tenth of a foot.
Accepted Solution
A:
20.9 ft This is a right triangle trigonometry question because N is 90 degrees. MN is adjacent to M and LM is the hypotenuse. Adjacent any hypotenuse use the cosine function. [tex]cos \theta = \frac{adj}{hyp}[/tex] plug in known values [tex]cos(17) = \frac{20}{x}[/tex] switch cos(20) and x using the products property [tex]x = \frac{20}{cos(17)}[/tex] plug into calculator to get 20.9 ft