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Popular Word Problems >

The area of a circle is 81pi mm^2. What’s its circumference?

Solution

T h e a re a o f a c i rc l e i s 81 π m m^{2} . Wha t ’ s i t s c i rc u m f ere n ce ?

Solution

c i rc u m f ere n ce : 18 π mm

+1

Decimal

56.54866 \dots

Solution steps

Given:

a re a : 81 π m m^{2}

Radius given

A re a = 81 π : r = 9

Circle circumference given

r = 9 : C = 18 π

c i rc u m f ere n ce : 18 π mm

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