8 in traveling 34 of the way around a traffic circle a car t

8.

in traveling 3/4 of the way around a traffic circle, a car travels 0.206 mi. what is the radius of the traffic circle?

the radius of the traffic circle is _____ mi.

Solution

car travels along the circle through an angle of pi +pi/2 = 3pi/2

So,Perimeter = 2pir

for 3pi/2 permieter = (2pir)*(3pi/2 /2pi)

= 3pir/2

Now 3pi*r/2 = 0.206

r = 0.412/3pi = 0.0437 miles ( radius)