Answer:
15 π meters
Step-by-step explanation:
1) Since vertical angles are equal, angle BPD = 60 degrees and angle DPC = 120 degrees.
2) Now if you would add angles APB, BPD, and DPC, you would get the measure of arc ADC: 120 degrees + 60 degrees + 120 degrees = 300 degrees. So the measure of arc ADC = 300 degrees.
3) Now you would set up a ratio comparing the measure of arc ADC to 360 degrees: 300/360.
4) Then, simplify 300/360 to 5/6.
5) Next, do this: 5/6 x 2 π r --> 5/6 x 2 π 9. You should get 15 π.
6) So, the exact length of arc ADC is 15 π meters.
<em>Hope this helps! :)</em>