2007-12-27 20:10:20 · 6 answers · asked by i 1 in Science & Mathematics ➔ Mathematics
I assume you are talking about regular decagon? If that is the case then I think I can answer it. A regular decagon is a regular polygon with 10 sides.
The formula is: Area=1/2(ap), where a = apothem, p = perimeter of the polygon.
You can go to the following website to read the meaning of apothem and other geometric terms you will need to understand the formula.
From: http://www.sparknotes.com/math/geometry2/measurements/section6.rhtml
teddy boy
2007-12-27 20:39:08 · answer #1 · answered by teddy boy 6 · 0⤊ 0⤋
This Site Might Help You.
RE:
an equation for area or circumference of a decagon?
2015-08-11 23:53:56 · answer #2 · answered by Annetta 1 · 0⤊ 0⤋
A general formula for the area of any regular polygon is NV^2sin(pi/N)cos(pi/N) where N is the number of sides and V is the distance from the center of the polygon to the vertex.
2007-12-27 22:36:05 · answer #3 · answered by stanschim 7 · 0⤊ 0⤋
http://mathforum.org/dr.math/faq/formulas/index.html
just click on Regular Polygon, this will show you how to find the area, as for the circumference, use
R = a csc(alpha/2)/2
2007-12-27 21:50:41 · answer #4 · answered by Sherman81 6 · 0⤊ 0⤋
OMG I JUST DID THIS IN MATHS to figure out the area: pi r squared and circumferance: 2 pi r r = radius
2016-03-13 21:50:31 · answer #5 · answered by Anonymous · 0⤊ 0⤋
P = 10s
A = 10(s/2)(s/2)tan18° ≈ 0.8122992s^2
2007-12-27 20:40:02 · answer #6 · answered by Helmut 7 · 0⤊ 0⤋