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how do you solve (b)?

 Jan 16, 2022
 #1
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b)   Take 1/5 th of the pentagon as shown below

 

     we need to find 'b'   (which is 1/10 th of the perimeter)

         calculate the area of 10 of these triangles = 6 

              10 *  1/2 b h

              10 * 1/2 ( hyp sin36 * hyp sin54)  = 6

                             hyp^2 sin36 sin 54 = 1.2

                             hyp = 1.588556        then   'b' = hyp * sin 36 = .9337296      perimeter = 10 * b =  9.337296

 

Now do the same for the larger pentagon   to   get tthe ratio of the perimeters   (basically do the above calculations wth '6' changed to 73.5)    

 

 Jan 19, 2022

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