Pentadecagon

Calculate the area of a regular 15-sides 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



Did you find an error or inaccuracy? Feel free to write us. Thank you!







Tips for related online calculators
See also our trigonometric triangle calculator.

 
We encourage you to watch this tutorial video on this math problem: video1

Related math problems and questions: