geometry regular polygon

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a=?
s=10.5cm
A= 19,887.5cm squared

Pentagon

A=asn/2
19,887.5cm=a*10.5*5/2
39775=52.5a
a=757.61cm?
am i correct?

regular nonagon
a=9.6cm
A=302.4cm squared
find perimeter thanks!

• geometry regular polygon -

302.4cm^2

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