Answer:
cos(π/6) = (√3)/2
Explanation:
The mnemonic SOH CAH TOA reminds you ...
Cos = Adjacent/Hypotenuse
You know that π/6 radians is 180°/6 = 30°, so you can find the adjacent side and hypotenuse in the triangle with the 30° angle. The figure then tells you ...
cos(30°) = Adjacent/Hypotenuse = (√3)/2
So, your answer is ...
cos(π/6) = (√3)/2