Pentadecagon

Calculate the area of a regular 15-side polygon inscribed in a circle with a radius r = 4. Express the result to two decimal places.

Correct answer:

S =  48.8084

Step-by-step explanation:

n=15 r=4  α=2 n2π=2 152 3.14160.2094  sin α = a/2 : r  a=2 r sinα=2 4 sin0.20941.6633 cos α = h:r  h=r cosα=4 cos0.20943.9126  S1=2a h=21.6633 3.91263.2539  S=n S1=15 3.2539=48.8084



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