geometry circle

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Help

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@short heart help

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draw lines AO, CO, OB, and OD, then:
AO = CO = OB = OD = r
AE = EB = CF = FD = sqrt(r² - 3²)
AB = AE + EB = 2 sqrt(r² - 9)
CD = CF + FD = 2 sqrt(r² - 9)
hence AB = CD

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What is 2nd step

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they are all radius

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AE is radius?

I mean 3rd step

That sqrt(r^2 - 3^2)

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Pythagoras theorem, cuz of right angles

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AE = EB = CF = FD = sqrt(r² - 3²)

This

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yes Ik

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But idk

How

It became so

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triangle AEO is a right-angled triangle, with AO = r and OE = 3, so:
AE² + 3² = r²
AE² = r² - 3²
AE = sqrt(r² - 3²)

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Oh

3rd step

How it came

Nvm

AB = AE + EB = how this = 2 sqrt(r² - 9)