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What is the area of a regular dodecagon (12 sides) with side length of 9 cm and apothem of 16.8 cm?

What is the area of a regular dodecagon (12 sides) with side length of 9 cm and apothem-example-1

1 Answer

3 votes

For this case we have that the area of a regular polygon is given by:


A = \frac {P * a} {2}

Where:

P: It is the perimeter

a: It is the apothem

Since we have a dodecagon, then the perimeter is:


P = 9 * 12\\P = 108 \ cm ^ 2

Then, the area is:


A = \frac {108 * 16.8} {2}\\A = 907.2 \ cm ^ 2

ANswer:

Option B

User Doug Porter
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