How do you find the value of #cos(pi/3) #?

1 Answer
Alan P.
Sep 19, 2016

#cos(pi/3)=color(green)(1/2)#

Explanation:

Consider an equilateral triangle with sides of length #2#
Since the interior angles are all equal and have a sum of #pi# radians,
each angle is #pi/3#

Dividing the triangle into halves as in the image below
and remembering the definition of #cos# as #("adjacent side")/("hypotenuse")#

We see that #cos(pi/3)=1/2#
enter image source here

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