29
The given sum is what we would get if we were to compute the definite
But we can also compute this directly:
Now by amazing coincidence $9.3$ squared happens to evaluate to
which is good enough to pass for $86.5$. One more lucky coincidence: $9.3$ is easily multiplied by $\frac 23$. So we need to do $6.2$ times $86.5$ which yields
The $.3$ cancels ...
8
I finally got it!
Below is a detailed explanation
8
Four circles:
Five circles:
Six circles:
7
I'll take a shot at it
Arrived at as follows
First
Then
So
But
So
4
Best I've found so far is
but I haven't exhausted alternatives just yet
2
1
Sure, a 1×4√5 rectangle and a 1×√5 rectangle.
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