Π/12 is half of π/6, which is 30 degree
tan(α/2)=(1-cosα)/sinα)
plug in the values: tan(π/12)=(1-cosπ/6)/sin(π/6)=(1-√3/2)/(1/2)=2-√3
Find 3/4 of 16.
16 * 3/4
48/4
12
<span>So she uses 12 gallons of gas.</span>
Area of a circle = (3.14) * r^2
d = 7
r = 3.5
a = (3.14) * 3.5^2
a = (3.14) * 12.25
a = 38.47