Answer:
[tex]A=906.9\ cm^2[/tex]
Step-by-step explanation:
A do-decagon is a polygon with 12 straight sides and 12 equal angles.
-The general formula for finding area of a do-decagon is given as:
[tex]A=3(2+\sqrt{3})s^2[/tex]
where s is the sides length.
-Given the sides dimension is 9cm, the area is calculated as;
[tex]A=3(2+\sqrt{3})s^2\\\\=3(2+\sqrt{3})\times 9^2\\\\=906.8883462\approx906.9\ cm^2[/tex]
Hence, the do-decagon's area is [tex]906.9\ cm^2[/tex]
