Question

according to this diagram, what is cos 23°? a. $\frac{5}{12}$ b. $\frac{12}{13}$ c. $\frac{5}{13}$ d. $\frac{12}{5}$ e. $\frac{13}{5}$ f. $\frac{13}{12}$

Explanation:

Step1: Recall cosine definition

In a right - triangle, $\cos\theta=\frac{\text{adjacent}}{\text{hypotenuse}}$.

Step2: Identify sides for 23 - degree angle

For the $23^{\circ}$ angle in the given right - triangle, the adjacent side is 12 and the hypotenuse is 13.

Step3: Calculate cosine value

So, $\cos23^{\circ}=\frac{12}{13}$.

Answer:

B. $\frac{12}{13}$