2.152636 cm. = (12 x 8) – (16 x pi ) this is the area of the small circle ( 45.734 squared cms ) the squared root of this amount is divided by pi ( 3.14159 ) it give you 2.152636 cm.
Another method that give me 2.157 cms is to draw a circle half the size of the big circle (2 cms) and place it at the center of the small circle by making an octagono I get that the circumscribe lenght of 2.157 cms.
is there a piece of information missing? As I have tried several strategies and keep getting r = r or 4 = 4
Are you using the 12? And pythagoras…
sorry ignore my comment I think I’ve solved it !
2.14359?
I get 2.1444 cms
Sorry is r2 = 2.14359360665022975737527008 cms
Yes
I’m not seeing it
Draw a right angled triangle where the hypotenuse is the 2 radii as shown
i got 1
Is it 2cm?
Yes and no, if you consider that (4- X)+(8-X)=4+X
2.152636 cm. = (12 x 8) – (16 x pi ) this is the area of the small circle ( 45.734 squared cms ) the squared root of this amount is divided by pi ( 3.14159 ) it give you 2.152636 cm.
Another method that give me 2.157 cms is to draw a circle half the size of the big circle (2 cms) and place it at the center of the small circle by making an octagono I get that the circumscribe lenght of 2.157 cms.
Final answer is a quadratic equation in r2 = (4 – r2) squared + ( 8 – r2 ) squared = ( 4 + r2 ) squared.
So I get 2.1444 cms