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Find the area of the regular 30 -gon with radius 7 mm.

 Apr 4, 2017
 #1
avatar+23252 
+1

A formula to find the area of a regular polygon given the radius is:

Area  =  r2 · n · sin( 360 / n ) / 2

          =  7· 30 · sin( 360 / 30 ) / 2

          =  7· 30 · sin( 12 ) / 2

          =  5.09 mm2     (approximately)

 Apr 5, 2017
 #2
avatar+129847 
+1

The area  is given by :

 

30 * (1/2) * (7^2) * sin (12°)  ≈   152.8 mm^2  

 

[ I think geno's answer would be the same.....]

 

 

cool cool cool

 Apr 5, 2017

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