Ask your own question, for FREE!
Mathematics 23 Online
OpenStudy (anonymous):

Answer this Math Question!

OpenStudy (anonymous):

let me draw the diagram

OpenStudy (akashdeepdeb):

Diagram?

OpenStudy (anonymous):

The radius of the larger circle is 10 cm. Find the area of the largest circle that will fit in the middle.

OpenStudy (anonymous):

this is toughest of all the problems i have solved

OpenStudy (anonymous):

hint(it's simple algebra of grade 9 0r 10)

OpenStudy (akashdeepdeb):

The radius of the LARGEST circle is 10cm?

OpenStudy (anonymous):

find the area of the blue circle

OpenStudy (akashdeepdeb):

The radius of the LARGEST circle? The orange circle radii is 10cm or what?

OpenStudy (anonymous):

10 cm

OpenStudy (anonymous):

largest circle radius is 10 cm

OpenStudy (akashdeepdeb):

Anything else given?

OpenStudy (anonymous):

nop!

OpenStudy (anonymous):

my internet connection is frequently disconnecting so i will get back on this question tommorow solve it till tommorow!!!!

OpenStudy (anonymous):

Radius of the largest circle(orange) is 10 cm. Find the area of the blue circle??

OpenStudy (dumbcow):

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 \[r(2\sqrt{2}+2) +r = 10\] \[r = \frac{10}{2\sqrt{2}+3} = 10(3-2\sqrt{2})\] \[Area = \pi r^{2} = 100(3-2\sqrt{2})^{2} \pi \approx 9.25\]

OpenStudy (akashdeepdeb):

How is R+r = sqrt2.R @dumbcow? :/

OpenStudy (asnaseer):

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 \(\pi r^2\)

Can't find your answer? Make a FREE account and ask your own questions, OR help others and earn volunteer hours!

Join our real-time social learning platform and learn together with your friends!
Can't find your answer? Make a FREE account and ask your own questions, OR help others and earn volunteer hours!

Join our real-time social learning platform and learn together with your friends!