Answer: third optionStep-by-step explanation: As you can see in the figure attached, the triangle is a right triangle. Then, you can calculate cosA as it is shown below: - You need to remember the following: [tex]cos\alpha=\frac{adjacent}{hypotenuse}[/tex] - Now, you must substitute values. Based on the figure: [tex]adjacent=3\\ hyppotenuse=5[/tex] [tex]\alpha=A[/tex] Therefore, you obtain that cosA is: [tex]cosA=\frac{3}{5}[/tex]