find d radius of d circle...!!!

If inside a big circle exactly 24 small circles each of radius 2 can be drawn in such a way that each small circle touches the big circle and also touch both its adjacent small circles. Then the radius of the big circle is.........

a) 2(1+ cosec Î /24) B) [(1+tan Î /24) / cos Î /24]

c) 2(1+cosec Î /12) d) 2(sin Î /48 + cos Î /48)2 / sin Î /24

no need to solve it completely, juzz give d figure n procedure... (i'm a bit confused on what is d quick approach..!!!?)

well, for ur cross-checking, d ans is A,D

10 Answers

39
Dr.House ·

well cant we take the circles to be all lying inside the big circle along the circumference ?

1
The Scorpion ·

yeah, dats what d question means...

give some initial steps plz or atleast a diagram...!!!

1
°ღ•๓яυΠ·

aagaya :)

c d cenral angle for each equlatral tringle formed is 2pi/n for n sides polygon nw here u hav 24 sides
so itz 2pi/24

nw
(consider one of those trngles )

drwn a perpendicular frm d center to d side join d two centres

nw sin(pi/24) =2/hypo

d radius of bigger required circle is hypo+2

so itz

2cosec(pi/24)+2

1
°ღ•๓яυΠ·

39
Dr.House ·

the author of the question himself has said answers are A and D.

1
skygirl ·

arey nahi mereko neend ayi/aya hai ......... [dunno hindi grammar :P]

1
°ღ•๓яυΠ·

A n D both r rite

1
The Scorpion ·

thanx for d solution Ms. X (whats in name :P)... :D

well, derive option D from A... for one more pink post... ;) :P ..... (kiddin, i'll do it myself)...

thanx... :)

1
skygirl ·

nice prob MAK...

1
°ღ•๓яυΠ·

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