(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

Find the blue colored surface area.

1 http://img338.imageshack.us/img338/1630/graph1zd7.png [Broken]

The radii of the circles are 3 cm and 1 cm.

2 Find the surface area of the rosette inside the equilateral triangle with side a.

http://img87.imageshack.us/img87/2590/graph2dj9.png [Broken]

2. Relevant equations

3. The attempt at a solution

I have no idea what to do with the first one.

For the 2nd one the area of the rosette inside the triangle should be the area of 3 segments minus the area of the triangle.

Here's a picture of what I did, with one circle only:

http://img339.imageshack.us/img339/4650/circlerd9.png [Broken]

This is what I got: [tex] \frac{a^2}{6}(2 \pi - \frac{3 \sqrt {3} }{2}) [/tex]

But the book says it's [tex] \frac{a^2}{6}(2 \pi - 3 \sqrt {3} ) [/tex], so can anyone check it?

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# Homework Help: Some geometry

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