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# Geometry/Circles (and Zombies)

Question
Hello, I am helping my little sister with her homework. I am a little stumped with the problem below.

"zombies have invaded our chess game. Because they are not bright, mrs. greene is running circles around the horde. if she is 49 feet away from the horde, how much distance will she cover in one revolution?"

I believe the question is trying to ask what the circumference is. C= πr^2= π(49)^2=7542.96. But I am not sure if that's true. Hope you can help.

Thanks.

Hey Caroline,

The question is indeed asking for the circumference.  However, C=2πr is the equation you need, not πrē (that would give you the area of the circle).  Thus C=2π(49)=98π=307.88

So, Mrs. Greene will cover a distance of 307.88 feet.

Cheers,
Azeem
Questioner's Rating
 Rating(1-10) Knowledgeability = 10 Clarity of Response = 10 Politeness = 10 Comment Thank you so much, especially for the quick response! she has a test tomorrow :)

Geometry

Volunteer

#### Azeem Hussain

##### Expertise

I welcome your questions on algebra, 2D and 3D geometry, parabolic functions and conic sections, and any other mathematical queries you may have.

##### Experience

4 years as a drop-in and by-appointment tutor at Champlain College. Private tutor for dozens of clients over the past 8 years.

Publications
CALPHAD: Computer Coupling of Phase Diagrams and Thermochemistry

Education/Credentials
Bachelor of Science, Major Mathematics and Major Economics, McGill University, 2014. Diploma of Collegiate Studies; Pure and Applied Science, Champlain College Saint-Lambert, 2010.