find the area .
A regular octagon with radius 20 inches .

Question

find the area . 
A regular octagon with radius 20 inches .

anonymous · Answer

It's approximately 1931.37 square inches.

anonymous · Answer

How ?

anonymous · Answer

I'll be honest, I googled it. But the formula is here A=2(1+2)a2

anonymous · Answer

Thats what i usually do .
the formula is area = apothem * perimeter.. or 1/2 * bc(sin A) 
Which basically means bc is the side numbers times sin( angle degree) divided by 2

anonymous · Answer

I'd just guess to plug in the data. I'm not exactly sure what an apothem is, unfortunately

anonymous · Answer

@satellite73

anonymous · Answer

Oh its algebra 2

anonymous · Answer

Ah, here we go, an apothem is just the radius of the in-circle of a polygon. Which can be found using the length of a regular polygon and this equation

anonymous · Answer

$$apothem = s/(2\tan(180/n))$$
S is the length of any of the sides, while N is the number of sides

anonymous · Answer

i dont even know the length of the side, i have my notes from class with me they just dont help .

anonymous · Answer

so that should be 20/2tan(180/8)

anonymous · Answer

ah oh crab, the radius is 20, not the side, my bad

anonymous · Answer

well there's a neato octagon calculator here, but I can't really take the time to teach myself this lil branch of algebra at the moment, I'm really sorry lass http://rechneronline.de/pi/octagon.php