What is the arc length of an angle of 2 pi/3 radians firmed on the unit cirlce

Provide an example of a trigonometric function and describe how it is transformed from the standard trigonometric function f(x) = sin x, f(x) = cos x, or f(x) tan x using key features.

Could someone with number 1 and 2

Timmy uses 1 1 2 cups of sugar for every 2 gallons of lemonade he makes. how many cups of sugar would timmy use if he makes 13 gallons of lemonade?