Final answer:
The Roman or round arch uses counterweights in the form of a keystone and gravitational forces to support wider openings without collapsing.
Step-by-step explanation:
The subject at hand refers to an architectural element, more precisely to the type of arch that uses counterweights to support a wider opening. In this regard, it is clear that the Roman arch, also known as the round arch, is in focus. The Romans incorporated a keystone, a wedge-shaped stone in the center at the top of the arch, which, due to its shape, directs vertical forces from the arch's apex out along the curve of the arch to the support pillars on each side. This design effectively uses gravitational forces as a counterweight, allowing the arch to span wider distances without collapsing.
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