Geometry problem(quick)

[paradise!]

quick guys what to do if 40 and live with mom , help brain melting

fixed

not quite, what i meant by doing the same thing going around the other way is this:

lower left corner: radius 100
upper left corner: radius 80
upper right corner: radius 70
lower right corner: radius 90

the lower right corner has radius 90 cuz the horse can go that way too instead of wrapping the rope around the entire barn by going clockwise.

what you end up with is 4 circles, the tricky part is subtracting the overlapping areas, and of course subtracting the 20 x 10 = 200 square feet of the barn itself

edit: it may help to do it on graph paper

how can i tell the area of overlap? or does it work out like a 1/4 of the circle which i just subtract? can u edit my original pic, it would help loads.

[Vatican Assassin]

god i rememebr doing this exact problem in geo about 15 years ago, and when they expalined it, it was so simple. you definately have to use the info ive given, but right now my brain is telling me i shouldnt have said this was ez. unfortunately, i am writing a paper on lesbianism for grad school right now and i can't take the time do work it out. this problem is so, i guess, famous? that you can probably google it somehow, gl man.

[Vatican Assassin]

here ya go this should do it
http://mathforum.org/library/drmath/view/51830.html

[Ewan]

Ok, drawing it out, it comes across harder than i had initially anticipated.

Firstly you get

3/4 * (pi*100^2) (yellow section)
then you get
+ 1/4 * (pi*90^2) (green)
+ 1/4 * (pi*80^2) (red)

Now, from this diagram, we see where the main problem lies:

see attached pic

The only way I can think of doing it, is to approximate (it's a pretty close approximate though):

The brown section is very close to another quarter circle with radius 70, (both straight sides = 70 and the curved side is very close to an actual quarter circle).

So now you get the final answer as:

11375pi - 1225pi - 200 =
10150pi - 200

Alternatively, it's a trick question and he is inside the barn so can graze 200ft.

If this is a school question it's probably the first one. If it's some "online test" or "fun quiz" or "brain teasers!" or something, it's probably the cheeky trick one.


EDIT: Well there you have it, the one posted by Vatican gets around the approximation problem, I am pretty sure the answers would be very close though. I think it's a classic example of how an Engineer would do it (use approximations) vs how a mathematician would do it (exact, but worth the effort for that tiny bit more accuracy?).

EDIT2: I am an idiot and was using 2*pi*r instead of pi*r^2 for area of a circle.

[D1st0rt]

edit: mb

did my sketch right, then messed up the computer drawing and didn't notice it was different

[paradise!]

Ok, drawing it out, it comes across harder than i had initially anticipated.

Firstly you get

3/4 * (pi*100^2) (yellow section)
then you get
+ 1/4 * (pi*90^2) (green)
or
+ 1/4 * (pi*80^2) (red)

what do u mean by OR, then do i also add this total to the radius 70 one, where do i subtract the overlap.

[paradise!]

here ya go this should do it
http://mathforum.org/library/drmath/view/51830.html

EDIT: i think i got, pretty simple trig topic, i think i can get justa lil work, sector formula etc.. i get it sorta.

[Ewan]

what do u mean by OR, then do i also add this total to the radius 70 one, where do i subtract the overlap.

yeah sorry forget the or, that was before I re-thought it slightly.

so it's

yellow + red + green - brown

[Nickname]

in this thread conc ages 10 years and moves back home. Also, a horse eats a lot of grass.

[Pandagirl!]

There is no grass; the cow lives in Alaska.

[PH]

that's not a fucking horse.

[ConcreteSchlyrd]

horse ate my fuking appels

[paradise!]

yeah sorry forget the or, that was before I re-thought it slightly.

so it's

yellow + red + green - brown

ok, are you sure it is correct? 10 pts extra cred hinge-ing on this. :grin:

[PH]

IT'S STILL NOT A fUCKING HORSE.

[paradise!]

IT'S STILL NOT A fUCKING HORSE.

ITS A FUCKIn PEICE OF DOGSHIT OK? I FUCKING GOT THE DAMN SPRAYCAN, CLICKED BLACK AS COLOR, AND FUCKIN SPRAYED OK? I FUCKIN SPRAYEd AND THATS WHAT CAME UP. SO I GUESS ITS NOT A HORSE.