Question

Find the measure of the indicated angle to the nearest degree.A. 63B. 25C. 31D. 27

Answer 1

The point of the problem is to remember the cosine relation. It says, in this case, that

`\cos (?)=\frac{\text{adjacent side}}{Hypotenuse}\Rightarrow\begin{cases}\text{adjacent side}=6 \\ \text{Hypotenuse}=13\end{cases}\Rightarrow\cos (?)=(6)/(13)`

Converting the last equation by the inverse function, we get

`?=\cos ^(-1)((6)/(13))\approx62.5`

For the first decimal place (5) equals 5, and by the rounding rule to the nearest degree, we get 63. The answer is A.