The threefold structure of the triangle is interpreted over multiple levels. Some of these visualisations are:
1). Creation, Preservation, and Destruction, i.e. Brahma, Vishnu, and Shiva.
2). The three tendencies: the neutral, the positive and the negative - Sattva, Rajas, and Tamas.
3). The three Vedas: Rig, Yajur, and Sam.
4). Past, Present, and Future.
5). The three seasons: Spring, Summer, and Winter.
6). The three main pilgrimages: Prayag, Gaya, and Kashi.
When used in a yantra, a triangle is either inverted or upright. The inverted triangle is a symbol of feminine power, the creative essence of the universe, also known as Shakti.