wow, really complicated.

Titanic or the Cookies?

]]>wow, really complicated.

]]>I am on the verge of post # 200

and this an occassion for me to celebrate,

I shall take a big chunk of thhat ]]>

Mathsy gets first choice.

]]>

I got the sectors the wrong way around.

Length x sector's angle: cos-¹(1-x²/1800)

Length 30 sector's angle: cos-¹(x/60)

So, the latest formula is =900*PI()*ACOS(1-B8*B8/1800)/(2*PI())+B8*B8*PI()*ACOS(B8/60)/(2*PI())-SQRT((30+B8/2)*(B8/2)*(B8/2)*(30-B8/2))

Edit: And it works perfectly! Cookies for everyone!

To the nearest cm, the goat's leash is 34.76m long.

All I can see is that you haven't divided the sector areas by the number of whatever you're measuring by. Excel works with radians by default so try this:

=900*PI()*ACOS(B8/60)/(2*pi()) + B8*B8*PI() *ACOS(1-B8*B8/1800)/(2*pi()) - SQRT((30+B8/2) * (B8/2)* (B8/2) * (30-B8/2))

( Gee, if we all have to be worried about making mistakes then we may as well take the "Fun" off the forum name. )

Still not quite there ... maybe i am not getting my formula right.

=900*PI()*ACOS(B8/60) + B8*B8*PI() *ACOS(1-B8*B8/1800) - SQRT((30+B8/2) * (B8/2)* (B8/2) * (30-B8/2))

If you have a chance, see if you can get it working, then just delete the last two or three posts and show the world how neat and perfect we are!

]]>The real area: 900Π*cos-¹(x/60)/360 + x²Π*cos-¹(1-x²/1800)/360 - √((30+x/2)(x/2)²(30-x/2))

Sorry again!

Pi is there, it just looks weird: Π

By the way, I tried that formula in excel with "30" for x and got -387.617, have we somehow created anti-grass?

Formula: =ACOS(B8/60) + ACOS(1-B8*B8/1800) - SQRT((30+B8/2) * (B8/2)* (B8/2) * (30-B8/2))

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