## Baseball diamond "construction"

The Official Baseball Rules describe how to lay out a baseball diamond as
follows:

**Rule 2**

The Playing Field

2.01 Layout of the Field

...

When location of home base is determined, with a steel tape measure
127 feet, 3 3/8 inches [*] in desired direction to establish second
base.

From home base, measure 90 feet toward first base; from second
base, measure 90 feet toward first base; the intersection of
these lines [!] establishes first base.

From home base, measure 90 feet
toward third base; from second base, measure 90 feet toward third
base; the intersection of these lines [!] establishes third base.

The distance
between first base and third base is 127 feet, 3 3/8 inches.

...

[This is not a true geometric construction, because a tape measure is used,
but it is a way to create (nearly) right angles at first and third bases.]

[*] 90*sqrt(2) feet = 127.27922... feet

127 feet 3 3/8 inches = 127.28125 feet, an error of ~0.02 inches.

[!] Arcs of circles!

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