Given: A right-angled triangle with AB=30 units, BC=40 units, and AC=50 units.
Required: To find the trigonometric ratio cos(A).
Explanation: The trigonometric ratio cosine is defined as the ratio of the adjacent side to the triangle's hypotenuse.
[tex]cos(\theta)=\frac{adjacent\text{ }side}{hypotenuse}[/tex]
Here, in triangle ABC, the adjacent side for angle BAC is AB, and AC is the triangle's hypotenuse.
Hence
[tex]\begin{gathered} cos(A)=\frac{AB}{AC} \\ =\frac{30}{50} \\ =\frac{3}{5} \end{gathered}[/tex]
Final Answer:
[tex]cos(A)=\frac{3}{5}[/tex]
