Question

The diameter of the larger circle is 12.5 cm.

The diameter of the smaller circle is 3.5 cm.

What is the approximate area of the larger circle?

Answer 1

The answer is: " 122.65625 cm² " ; or, write as: " 122
`(21)/(32)` cm² " .
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Note:
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The area, "A", of a circle:

A =
`\pi` * r² ;

in which: A = area of the circle;


`\pi` = 3.14 ;

r = radius ;

To calculate radius, "r" = diameter/2 = 12.5 cm/2 = 6.25 cm .

r = 6.25 cm ;

So, to calculate the area, "A" of the circle:

A =
`\pi` * r² ;

Plug in the values to find the Area, "A" of the circle:

A = 3.14 * (6.25 cm)² ;

A = 3.14 * (6.25)² * cm² ;

A = 3.14 * 39.0625 * cm² ; Note that "39.0625" = "
`(1)/(16)`" .

A = 122.65625 cm² ; or, write as: " 122
`(21)/(32)` cm² " .
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