Circle with equilateral triangle
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How to use property of equilateral triangle which is given in the question .
geometry triangle circle
$endgroup$
add a comment |
$begingroup$
How to use property of equilateral triangle which is given in the question .
geometry triangle circle
$endgroup$
add a comment |
$begingroup$
How to use property of equilateral triangle which is given in the question .
geometry triangle circle
$endgroup$
How to use property of equilateral triangle which is given in the question .
geometry triangle circle
geometry triangle circle
edited 2 hours ago
Dr. Mathva
2,104425
2,104425
asked 5 hours ago
![](https://lh6.googleusercontent.com/-pnz0SGqDDOk/AAAAAAAAAAI/AAAAAAAAC_I/7tzuLtVD1-o/photo.jpg?sz=32)
![](https://lh6.googleusercontent.com/-pnz0SGqDDOk/AAAAAAAAAAI/AAAAAAAAC_I/7tzuLtVD1-o/photo.jpg?sz=32)
Abhinov SinghAbhinov Singh
1394
1394
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2 Answers
2
active
oldest
votes
$begingroup$
Here's a picture, with a bunch of useful things drawn in and labeled:
The center of the circles are marked with dots; $O$ is the center of the yellow circle and $E$ is the center of the green circle.
So now, what's the ratio of $ED$ to $AE$?
$endgroup$
add a comment |
$begingroup$
According to Jmerry's diagram,
$$2R = AE + ED = r+ frac{r}{cos60°} = r+ frac{r}{1/2} = r+ 2r$$
Thus,
$$frac{R}{r}=frac{3}{2}$$ or
$$frac{r}{R}=frac{2}{3}$$
$endgroup$
$begingroup$
Therefore $$frac{text{yellow}}{text{green}}=frac{R^2pi-r^2pi}{r^2pi}=frac{R^2pi}{r^2pi}-1=big(frac{R}{r}big)^2-1=big(frac{3}{2}big)^2-1=frac{5}{4}$$ Thus $$frac{text{green}}{text{yellow}}=frac{4}{5}$$
$endgroup$
– Dr. Mathva
2 hours ago
add a comment |
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2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
$begingroup$
Here's a picture, with a bunch of useful things drawn in and labeled:
The center of the circles are marked with dots; $O$ is the center of the yellow circle and $E$ is the center of the green circle.
So now, what's the ratio of $ED$ to $AE$?
$endgroup$
add a comment |
$begingroup$
Here's a picture, with a bunch of useful things drawn in and labeled:
The center of the circles are marked with dots; $O$ is the center of the yellow circle and $E$ is the center of the green circle.
So now, what's the ratio of $ED$ to $AE$?
$endgroup$
add a comment |
$begingroup$
Here's a picture, with a bunch of useful things drawn in and labeled:
The center of the circles are marked with dots; $O$ is the center of the yellow circle and $E$ is the center of the green circle.
So now, what's the ratio of $ED$ to $AE$?
$endgroup$
Here's a picture, with a bunch of useful things drawn in and labeled:
The center of the circles are marked with dots; $O$ is the center of the yellow circle and $E$ is the center of the green circle.
So now, what's the ratio of $ED$ to $AE$?
answered 4 hours ago
![](https://i.stack.imgur.com/oaa4s.png?s=32&g=1)
![](https://i.stack.imgur.com/oaa4s.png?s=32&g=1)
jmerryjmerry
12.8k1628
12.8k1628
add a comment |
add a comment |
$begingroup$
According to Jmerry's diagram,
$$2R = AE + ED = r+ frac{r}{cos60°} = r+ frac{r}{1/2} = r+ 2r$$
Thus,
$$frac{R}{r}=frac{3}{2}$$ or
$$frac{r}{R}=frac{2}{3}$$
$endgroup$
$begingroup$
Therefore $$frac{text{yellow}}{text{green}}=frac{R^2pi-r^2pi}{r^2pi}=frac{R^2pi}{r^2pi}-1=big(frac{R}{r}big)^2-1=big(frac{3}{2}big)^2-1=frac{5}{4}$$ Thus $$frac{text{green}}{text{yellow}}=frac{4}{5}$$
$endgroup$
– Dr. Mathva
2 hours ago
add a comment |
$begingroup$
According to Jmerry's diagram,
$$2R = AE + ED = r+ frac{r}{cos60°} = r+ frac{r}{1/2} = r+ 2r$$
Thus,
$$frac{R}{r}=frac{3}{2}$$ or
$$frac{r}{R}=frac{2}{3}$$
$endgroup$
$begingroup$
Therefore $$frac{text{yellow}}{text{green}}=frac{R^2pi-r^2pi}{r^2pi}=frac{R^2pi}{r^2pi}-1=big(frac{R}{r}big)^2-1=big(frac{3}{2}big)^2-1=frac{5}{4}$$ Thus $$frac{text{green}}{text{yellow}}=frac{4}{5}$$
$endgroup$
– Dr. Mathva
2 hours ago
add a comment |
$begingroup$
According to Jmerry's diagram,
$$2R = AE + ED = r+ frac{r}{cos60°} = r+ frac{r}{1/2} = r+ 2r$$
Thus,
$$frac{R}{r}=frac{3}{2}$$ or
$$frac{r}{R}=frac{2}{3}$$
$endgroup$
According to Jmerry's diagram,
$$2R = AE + ED = r+ frac{r}{cos60°} = r+ frac{r}{1/2} = r+ 2r$$
Thus,
$$frac{R}{r}=frac{3}{2}$$ or
$$frac{r}{R}=frac{2}{3}$$
edited 1 hour ago
Oscar Lanzi
13k12136
13k12136
answered 3 hours ago
Mathew MahindaratneMathew Mahindaratne
562212
562212
$begingroup$
Therefore $$frac{text{yellow}}{text{green}}=frac{R^2pi-r^2pi}{r^2pi}=frac{R^2pi}{r^2pi}-1=big(frac{R}{r}big)^2-1=big(frac{3}{2}big)^2-1=frac{5}{4}$$ Thus $$frac{text{green}}{text{yellow}}=frac{4}{5}$$
$endgroup$
– Dr. Mathva
2 hours ago
add a comment |
$begingroup$
Therefore $$frac{text{yellow}}{text{green}}=frac{R^2pi-r^2pi}{r^2pi}=frac{R^2pi}{r^2pi}-1=big(frac{R}{r}big)^2-1=big(frac{3}{2}big)^2-1=frac{5}{4}$$ Thus $$frac{text{green}}{text{yellow}}=frac{4}{5}$$
$endgroup$
– Dr. Mathva
2 hours ago
$begingroup$
Therefore $$frac{text{yellow}}{text{green}}=frac{R^2pi-r^2pi}{r^2pi}=frac{R^2pi}{r^2pi}-1=big(frac{R}{r}big)^2-1=big(frac{3}{2}big)^2-1=frac{5}{4}$$ Thus $$frac{text{green}}{text{yellow}}=frac{4}{5}$$
$endgroup$
– Dr. Mathva
2 hours ago
$begingroup$
Therefore $$frac{text{yellow}}{text{green}}=frac{R^2pi-r^2pi}{r^2pi}=frac{R^2pi}{r^2pi}-1=big(frac{R}{r}big)^2-1=big(frac{3}{2}big)^2-1=frac{5}{4}$$ Thus $$frac{text{green}}{text{yellow}}=frac{4}{5}$$
$endgroup$
– Dr. Mathva
2 hours ago
add a comment |
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