<h3>
Answer: 18pi</h3>
============================================================
Explanation:
The area 81pi square meters leads to the radius 9 meters
Use the formula A = pi*r^2 to see why this is the case. You plug in A = 81pi and solve for r to get r = 9.
-----------------
Once you know the radius, you can determine the circumference C
C = 2*pi*r
C = 2*pi*9
C = 2*9*pi
C = 18pi
The circumference is the perimeter, or distance, around the circle.
Answer:
k = 6 : 5 : 4
Step-by-step explanation:
BC : AB : AC = 18 : 15 : 12 = 6 : 5 : 4
EF : DE : DF = 12 : 10 : 8 = 6 : 5 : 4
Answer: long range
Explanation: it mainly effects long range areas but can also affect short range if it need to