The unknown quantity which is the radius has a length of 49752/π yards.
How to find arc length?
The formula for the length of arc is;
S = rθ
where;
r is radius
θ is the central angle in radians
Now, we are given;
θ = 3π/4
S = 4146 * 9 yards
Thus, making r the subject and solving gives;
r = S/θ
r = (4146 * 9)/(3π/4)
r = 49752/π
Thus, the unknown quantity which is the radius has a length of 49752/π yards.
Read more about Arc Length at; https://brainly.com/question/2005046
#SPJ1
