Made a sketch from Tenth Ed. ARRL antenna book ... gotta love the used
bookstore

http://www.n3ox.net/files/bigwheel_sketch.pdf

All red circles go to one side of the feedline, all blue go to the
other.

Impedance if the antenna is resonant is apparently about 12 ohms,
suggested matching method is to make each element a little bit short so
that it's a bit capacitive at the desired center frequency and then use
a hairpin inductor to match to 50 ohms.

No details on specific lengths in my book here; just says that each
element is "one wavelength" ... If I'm calculating correctly, think
that you want to shorten the elements enough that the natural feedpoint
impedance of the three paralleled elements is about 12-j21 and then use
a hairpin inductor of about +j28 ohms as the shunt across the
feedpoint.

Dan