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8 votes
The area of circle Q is 412. Circle P is 4 times bigger. What is the area of circle P? What is the perimeter of circle P?

A of circle P =

Perimeter of circle P =

User Vassi
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1 Answer

8 votes
8 votes

Explanation:

that is not clearly defined.

what does "bigger circle" mean ? bigger area or bigger radius or diameter ? or even bigger circumference ?

I assume we mean here that the area is 4 times bigger.

then the area of P is

A of P = 4×412 = 1648

the perimeter (= circumference) of a circle is

C = 2×pi×r

with r being the radius.

the area of a circle is

A = pi×r²

since we have the area of the circle, we have to calculate backwards to find r, so that we can calculate the circumference :

1648 = pi×r²

r² = 1648/pi

r = sqrt(1648/pi) = sqrt(16×103/pi) = 4×sqrt(103/pi) =

= 22.90359562...

the circumference of P

C = 2×pi×r = 143.9075355...

User Himen
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