Question

Find the area of the regular polygon. Give the answer to the nearest tenth. decagon with a side of 4 cm
A. 123.1 cm2
B. 129.4 cm2
C. 246.2 cm2
D. 139.8 cm2

Answer 1

Area of regular polygon of side length \(s\) :

\(\large \dfrac{ns^2}{4} \cot (\frac{\pi}{n})\)

Answer 2

simply plugin \(s\), \(n\) values
and evaluate

Answer 3

n = number of sides
s = length of side

Answer 4

ohhh thanks for clarifying batman

Answer 5

Np, so give this a shot, and get back to us :P

Answer 6

Actually since we're using a decagon you can easily just use this:

\[A = \frac{ 5 }{ 2 }a^2\sqrt{5+2\sqrt{5}}\]

Where a is the side.

Answer 7

40^2/4 =400

Answer 8

decagon has 10 sides

Answer 9

It's A !

Answer 10

Correcto!