Question

please help!!
Calculate the area of the regular pentagon below:

A regular pentagon with side length of 11.8 inches and dotted line from center to middle of side of 8.1 inches.

Answer 1

it is simply 5 triangle

base = 11.8, height = 8.1

area of triangle - 0.5 base * height

Answer 2

and I multiply that

Answer 3

\(\Large A = \frac 14 \times n \times a^2 \times cot \frac {pi}{n} \)
A | area
n | number of sides
a | side length

Answer 4

pentagon has 5 sides... so n=5
and side length is 11.8... so a = 11.8