math grade 12
posted by ted .
What is the arc length if the central angle is 225 degrees and the radius of a circle is 3 cm?
pls help. i don"t get it

Arc length = rθ ...(1)
where r is radius and θ is central angle in radians.
To convert 225° to radians, multiply by (π/180) to get 225π/180=5π/4
Use formula (1) to calculate arc length, which should be in the same units as the radius. 
2*225*pie/360*3
should be the answer;)