Example: Solve the right triangle shown in the image below.
Solution
Regardless of orientation, you should be able to identify that the Hypotenuse of this right triangle is 14 cm and the given angle is \(\frac{2\pi}{9}\). The missing sides are the Opposite and Adjacent, so we will need to use the Sine (Opp/Hyp) and Cosine (Adj/Hyp) to solve the missing sides: \[ \solve{ \sin\left(\frac{2\pi}{9}\right)&=&\frac{Opp}{14}\\ Opp&=&14\sin\left(\frac{2\pi}{9}\right)\\ Opp&\approx&9 } \]\[ \solve{ \cos\left(\frac{2\pi}{9}\right)&=&\frac{Adj}{14}\\ Adj&=&14\cos\left(\frac{2\pi}{9}\right)\\ Adj&\approx&10.72 }\] Depending on how the question is asked, you may be required to give an exact answer (such as \(14\sin\left(\frac{2\pi}{9}\right)\) ) or approximate (such as 10.72). Make sure you check your directions in WebAssign. If no directions are provided, the best answer is the exact answer.