Sailors need to consider the speed of the wind when adjusting the sails on their boat.
The force F (in pounds per square foot) on a sail when the wind is blowing perpendicular to
the sail can be modeled by F=0.004v where v is the wind speed (in knots).
Find the wind speed that will produce a force of 2.5 pounds per square foot on the sail.

c.

step-by-step explanation:

she should of added 9^2 and 12^2. that is because it is a^2+b^2=c^2. c^2 is the hypotenuse and should always be bigger than the other two numbers. which is why she should of added 9 squared and 12 squared together instead of 15 squared.

thats not a system of equations, that is a solution

arc length = radius * x ( in radians)

6 * pi = 18 * x

divide by 18 on each side

6 pi / 18 = x

pi/3 = x

the angle is pi / 3 radians

or   60 degrees