The area of a circle is 78.5 square cm, and a subtending arc on a circle has an arc length of 6 pi. the estimated value of pi is 3.14. the measure of the angle sub tended by the arc is what?

We know that

area of a circle=pi*r²> r=√[area/pi
area=78.5 cm²
r=√[78.5/pi]> r=√25> r=5 cm

circumference=2*pi*r> 2*pi*5> 10*pi cm

if 360° (full circle) has a length of> 10*pi cm
 X> 6*pi cm
x=6*pi*360/(10*pi)> x=216°

the answer is 
216°