## anonymous one year ago help!

1. anonymous

@mathmath333

2. anonymous

3. IrishBoy123

think about $$1 - \frac {\pi r^2}{4r^2}$$

4. IrishBoy123

ie what it means

5. anonymous

is it A?

6. IrishBoy123

this might be be more helpful $$1−\frac {πr^2}{(2r)^2}$$

7. IrishBoy123

in your question, what is $$\pi r^2$$ ?!

8. IrishBoy123

and what is $$(2r)^2$$ ?!

9. Astrophysics

I just explained this to you geny :\

10. anonymous

but im confused

11. anonymous

i dont get any of this (2r)2

12. anonymous

can you just give it to me in a more simple way to find the formula please

13. IrishBoy123

|dw:1439326130671:dw|

14. IrishBoy123

|dw:1439326209798:dw|

15. IrishBoy123

|dw:1439326313116:dw|

16. Astrophysics

17. IrishBoy123

cheers astro! i want to become the Banksy of OS :-)

18. Astrophysics

Bahaha!

19. IrishBoy123

@geny55 you still there, mate? if this is not helping, truly just say so. i want to help, not hinder.

20. anonymous

its not :(

21. Astrophysics

Mhm ok well I think the problem you're having is understanding where the area comes from...so let me put it as simple as I can. So here is a square |dw:1439326678199:dw| the area is "inside" the square. So far so good?

22. IrishBoy123

@geny55 thank you for your honesty !

23. Astrophysics

|dw:1439326963001:dw| so since the length of all the sides are the same for the square we let the side = a, and to find the total area, we then take the length and multiply it by the width $A_{\square} = lw = a \times a = a^2$

24. Astrophysics

Maybe you should try deriving the area of circle yourself for fun :P

25. anonymous

im sorry i cant do this question :( i give up

26. IrishBoy123

oh @geny55 :(( not so. penguins are remarkable creatures. we've all seen the movies. do you know: what is the area of a circle of radius r ?!