Answer:
884. D
885. C ( changed my answer)
886. B
887.A
For number 844, the diameter if the fan is 12 inches. To find Circumference, multiply the radius by two and then pi. The radius of the fan is 6, multiplied by 2 is 12, and multiplied by pi gives 12 times pi.
885 says half of the area gives the circumference. So we can write a formula, (pi*r^2)/2=2*pi*r. If the radius were 4, this would make the equation true. So the answer is 4.
886. Circumference=2*pi*r
r=6.78
2*pi*6.78
13.56*pi
887.
3*3=9
13-3=10
10*23=230
230+9=239 units squared