Answer this Math Question!
let me draw the diagram
Diagram?
The radius of the larger circle is 10 cm. Find the area of the largest circle that will fit in the middle.
this is toughest of all the problems i have solved
hint(it's simple algebra of grade 9 0r 10)
The radius of the LARGEST circle is 10cm?
find the area of the blue circle
The radius of the LARGEST circle? The orange circle radii is 10cm or what?
10 cm
largest circle radius is 10 cm
Anything else given?
nop!
my internet connection is frequently disconnecting so i will get back on this question tommorow solve it till tommorow!!!!
Radius of the largest circle(orange) is 10 cm. Find the area of the blue circle??
Let R be radius of white circle Let r be radius of blue circle \[2R+r=10\] \[R+r = \sqrt{2}R\] solving for R in 2nd equation \[R = \frac{r}{\sqrt{2}-1} = r(\sqrt{2} +1)\] sub into 1st equation \[r(2\sqrt{2}+2) +r = 10\] \[r = \frac{10}{2\sqrt{2}+3} = 10(3-2\sqrt{2})\] \[Area = \pi r^{2} = 100(3-2\sqrt{2})^{2} \pi \approx 9.25\]
How is R+r = sqrt2.R @dumbcow? :/
Using this section of the circles: |dw:1379268073723:dw| we get:\[\begin{align} r+2R&=10\\ \therefore R&=\frac{10-r}{2}\tag{1}\\ 2R&=\sqrt{2}(r+R)\tag{2}\\ \therefore 10-r&=\sqrt{2}(r+\frac{10-r}{2})\qquad\text{(using (1))}\\ \therefore 20-2r&=\sqrt{2}(2r+10-r)=\sqrt{2}(r+10)\\ \therefore r(2+\sqrt{2})&=20-10\sqrt{2}=10(2-\sqrt{2})\\ \therefore r&=\frac{10(2-\sqrt{2})}{2+\sqrt{2}}=\frac{10(2-\sqrt{2})^2}{4-2}=5(4-2\sqrt{2}+2)\\ &=5(6-2\sqrt{2})\\ &=10(3-\sqrt{2}) \end{align}\] Use this to calculate the area of the blue circle as \(\pi r^2\)
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