CIRCLE HELP!!!

MAliCiOuSViCiOuz

New member
Joined
Aug 2, 2005
Messages
10
THE DIAMETER OF A CIRCLE IS 16 KILOMETERS. FIND THE AREA OF THE CIRCLE.



HOW DO YOU FIND THAT OUT?? PLEASE HELP ME! THANK YOU! I HAVE BEEN STRUGGLING WITH THIS PROBLEM! :(
[/list][/code][/quote]
 

stapel

Super Moderator
Staff member
Joined
Feb 4, 2004
Messages
15,943
Recall that the radius r is half of the diameter, and plug the radius into the area formula they gave you: "A = (pi)(r<sup>2</sup>)".

Eliz.
 

dark-kitsune

New member
Joined
Aug 2, 2005
Messages
28
Right!!! :D As stapel said.

So,...
16/2=8.

8 x 3.1428 will equal the area of the circle.

figure it ouT!!!
 

dark-kitsune

New member
Joined
Aug 2, 2005
Messages
28
and square it .sorry!
 

dark-kitsune

New member
Joined
Aug 2, 2005
Messages
28
sory. what i meant ro say was, 8 times 3.1428 and then square the total. got it?? my bad. sory if i confused u
 

tkhunny

Moderator
Staff member
Joined
Apr 12, 2005
Messages
9,791
Wow, I'm confused.

Let's see, Area of a Circle = [pi]*r<sup>2</sup>

Diameter = 16 km
Radius = Diameter/2 = 16 km / 2 = 8 km <== Notice the units.

Area = [pi]*(8 km)<sup>2</sup> = [pi]*64 km<sup>2</sup> <== Notice the units.

If you need a decimal value, let your calculator tell you what [pi] is. I get about 201.062 km<sup>2</sup>

P.S. Did you notice the units?
 

dark-kitsune

New member
Joined
Aug 2, 2005
Messages
28
So then,

16/2=8

8<sup>2</sup>=64

then (pi)(64)= 201.06 rounded to the nearest tenth.
 

dark-kitsune

New member
Joined
Aug 2, 2005
Messages
28
im right, right? :?: :?
 

Gene

Senior Member
Joined
Oct 8, 2003
Messages
1,904
Dai jobu desu. Despite all the help.
----------------
Gene
 

dark-kitsune

New member
Joined
Aug 2, 2005
Messages
28
what the heck does that mean???
:?:
 

Gene

Senior Member
Joined
Oct 8, 2003
Messages
1,904
It means your screen name fooled me and you are right.
-----------------
Gene
 

dark-kitsune

New member
Joined
Aug 2, 2005
Messages
28
oh.
 

tkhunny

Moderator
Staff member
Joined
Apr 12, 2005
Messages
9,791
dark-kittsune said:
(pi)(64)= 201.06 rounded to the nearest tenth.
Still, no.

1) Where are your units?
2) "nearest tenth"? Better count that again.

Who posted this problem, anyway?
 

Denis

Senior Member
Joined
Feb 17, 2004
Messages
1,495
My head is sadly shaking to the tune of "boy oh boy"...
 

dark-kitsune

New member
Joined
Aug 2, 2005
Messages
28
my bad then.
 
Top