Yes, you're sketch is wrong, but you did clarify that A & C are along the string, so you have it.
BTW - the triangles aren't congruent, they're similar.
Note- this is my method for measuring with the fork off the bike, but I wouldn't take the fork off to do it this way. On the bike, any variation of the flip the fork and average is faster and comparably accurate (if done right).
So, how about a bet.
We'll need a fork of known rake and a volunteer who doesn't know the rake. Let him measure the rake by the various methods proposed. I'll bet a night's beer supply that he comes closest to the right answer by my method.
Any takers?
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Just because I'm tired of arguing, doesn't mean you're right.
“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN
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