The area of a circle is 16 pi cm2. What is the circle's circumference?

Answer 1

Sadie Allen

#"circumference "=8pi" cm"#

#"area of a circle "=pir^2larr" r is the radius"#

#"area is given as "16pi#

#rArrpir^2=16pilarr" divide both sides by "pi#

#rArrr^2=16rArrr=4#

#"circumference "=2pir=2pixx4=8pi" cm"#

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Answer 2

Aurora Ayala

The circumference of a circle can be found using the formula ( C = 2\pi r ), where ( r ) is the radius of the circle. Given that the area of the circle is ( 16\pi ) cm², we can find the radius using the formula for the area of a circle ( A = \pi r^2 ). Rearranging the formula to solve for ( r ), we get ( r = \sqrt{\frac{A}{\pi}} ).

Substitute ( A = 16\pi ) cm² into the formula to find ( r ):

[ r = \sqrt{\frac{16\pi}{\pi}} = \sqrt{16} = 4 \text{ cm} ]

Now, use the circumference formula ( C = 2\pi r ) with ( r = 4 ) cm to find the circumference:

[ C = 2\pi \times 4 = 8\pi \text{ cm} ]

So, the circumference of the circle is ( 8\pi ) cm.

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Answer from HIX Tutor

When evaluating a one-sided limit, you need to be careful when a quantity is approaching zero since its sign is different depending on which way it is approaching zero from. Let us look at some examples.