0
In every circle . . .
Area = (pi) x (radius)2
Diameter = 2 x radius
Circumference = (pi) x diameter
In this circle, Area = (pi) R2 = 81
R2 = 81/pi
R = sqrt( 81/pi )
Diameter = 2 x sqrt( 81/pi )
Circumference = (pi) x 2 x sqrt( 81/pi ) = 2 x sqrt( 81 pi ) = 18 sqrt(pi) = 31.9042 (rounded)
Still curious? Ask our experts.
Chat with our AI personalities
EzraFaith is not about having all the answers, but learning to ask the right questions.
Chat with Ezra
RossEvery question is just a happy little opportunity.
Chat with Ross
JordanLooking for a career mentor? I've seen my fair share of shake-ups.
Chat with Jordan
Add your answer:
Earn +20 ptsQ: What is the circumference of a circle with an area of 81?
Write your answer...
Submit
Still have questions?
Continue Learning about Other Math
How do you fund the circumference of circle when you know the area?
You dived the area by the circumference of the circle.
What is the formula for finding circumference and area of a circle?
Circumference of a circle is (pi * diameter). Area of a circle is (pi * r2).
What is the relationship between the circumference of a circle and the area of a circle?
Area = (Circumference squared)/4 pi Circumference = 2 sqrt(Area times pi)
What is the area of a circle with circumference 9.42in?
The area of a circle with circumference 9.42in is: about 7.061 square inches.
What is the circumference of a circle if the area is 81 pi square feet?
If: pi*radius2 = 81*pi sq ft Then: radius = 9 feet Circumference = 2*pi*9 = 56.549 feet rounded to 3 decimal places
Trending Questions
What is a radical neck dissection?
How did Euclid prove there is no largest prime?
When 70 percent of a number is added to the number the result is 272 what is the number?
If the volume of a sphere is 3000pie meters cubed what is the surface area of the sphere?
What fraction is equivalent to four fourteenth?
Four fifths of the sum of 4 and f?
What are all the numbers that when you times them together you get 72?
What is 1 million divided by 125?
John played a note on his tuba that vibrated the air 120 times per second. If he played the note for 4 seconds how many times did the air vibrate?
What is the greatest common factor of 40 80 and 128?
What is the volume of a cone with a height of 9 and radius of 3?
In a math class of 26 students each girl drew a triangle and each boy drew a rectangle there were 92 sides in all how many girls and boys were in the class?
The sum of three consecutive page numbers are 60 what are the page numbers?
The quotient of a number divided by 8 is equal to 12?
What is 310 minutes in hours?
When two line segments intersect and form a 90 degree angle?
What is 750000 divided by 12?
What is the only other flag that can be raised as high as the us flag?
Is only an adverb?
Which ones greater 5.1 or 5.01?
Copyright ©2025 Infospace Holdings LLC, A System1 Company. All Rights Reserved. The material on this site can not be reproduced, distributed, transmitted, cached or otherwise used, except with prior written permission of Answers.