The Tridentine Mass is the Roman Rite Mass that appears in typical editions of the Roman Missal published from 1570 to 1962. — Tridentine Mass, Wikipedia

A 30°-60°-90° right triangle, with sides 1 : √3 : 2, can be divided into three identical copies of itself:

30°-60°-90° Right Triangle — a rep-3 rep-tile…

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And if it can be divided into three, it can be divided into nine:

…that is also a rep-9 rep-tile

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Five of the sub-copies serve as the seed for an interesting fractal:

Fractal stage #1

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Fractal stage #2

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Fractal stage #3

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Fractal #4

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Fractal #5

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Fractal #6

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Fractal #6

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Tridentine cross (animated)

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Tridentine cross (static)

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This is a different kind of rep-tile:

Noniamond trapezoid

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But it yields the same fractal cross:

Fractal #1

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Fractal #2

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Fractal #3

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Fractal #4

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Fractal #5

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Fractal #6

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Tridentine cross (animated)

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Tridentine cross (static)

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Elsewhere other-available:

• Holey Trimmetry — another fractal cross