- Naditraya – The three nadis of the body are Ida, Pingala and Susumna.
- Purusatraya – The three classes of men are Uttama (best), Madhyama (mediocre) and Adhama (lowest).
- Pramanatraya- The three kinds of means of valid knowledge are Pratyaksa (what can be seen), Anumana (what can be logically inferred) and Agama (Verbal testimony)
- Brahmalaksanatraya- Suddha, Siva and Santa are the three Brahmalaksanas.
- Munitraya- The celebrated trio of sages are Panini, Patanjali and Katyayana.
- Yogatraya – The three kinds of yogas are: Jnanayoga, Bhaktiyoga and Karmayoga.
- Rititraya- The three ritis are Vaidarbhi, Pancali and Gaudi.
- Rupakatraya – Natya, Nrtya and Nrtta are the three rupakas.
10. Vaisyavrttitraya- The three duties of a Vaisya are Krishi (agriculture), Pasupalana (Breeding of cattle) and Vanijya ( trade) .
11. Saranatraya – Buddha, Dharma and Sangha are the three Saranas.
12. Siddhitraya- The following groups of three are considered to be Siddhitrayas. (a) Karmasiddhi, Yogasiddhi and Jnanasiddhi. (b) Aisvaryasiddhi, Jnanasiddhi and Vairagyasiddhi. (c) Sraddha, Vitta and Bhagya. (d) Mani, Mantra and Ausadha. (Siddhi means attainment, accomplishment).
13. Svaratraya -The different kinds of vowel are three in number namely Hrasva (short), Dirgha (long) and Pluta (prolated). Udatta, Anudatta and Svarita are also three different kinds of accent, i.e. the acute, grave and circumflexed).
14. Trimurti – Many world religions contain triple deities or concepts of trinity, including: the Christian Holy Trinity, the Hindu Trimurti(The Trimurti: Brahma the Creator, Vishnu the Preserver, and Shiva the Destroyer), The Three Jewels of Buddhism, the Three Pure Ones of Taoism, the Triple Goddess of Wicca.
15. In Vietnam, there is a superstition that considers it bad luck to take a photo with three people in it; it is professed that the person in the middle will die soon.
16. There is another superstition that it is unlucky to take a third light, that is, to be the third person to light a cigarette from the same match or lighter. This superstition is sometimes asserted to have originated among soldiers in the trenches of the First World War when a sniper might see the first light, take aim on the second and fire on the third.
17. A hat-trick in sports is associated with succeeding at anything three times in three consecutive attempts, as well as when any player in ice hockey or soccer scores three goals in one game (whether or not in succession). In cricket, if a bowler takes 3 wickets in a row it is called a hat trick.
18. A threepeat is a term for a team that wins three consecutive championships.
19. A triathlon consists of three events: swimming, bicycling, and running.
20. Three Phase – In electrical engineering, three-phase electric power systems have at least three conductors carrying alternating current voltages that are offset in time by one-third of the period.
21. One should not indulge in these three activities before noon – drinking alcohol, sex and gambling.
22. Three goddesses – Saraswati, Lakhsmi, Parvathi
23. Three goddesses of knowledge – Gayathri, Savithri, Saraswati (goddess of mind, goddess of deed and goddess of word)
24. Triple qualities of mind – Sattva, Rajas, Tamas.
25. Three states of consciousness – awake, sleep and dream.
26. God’s attributes are: omniscience, omnipresence, and omnipotence.
27. Thought, word, and deed, complete the sum of human capability. (Iccha Shakti, jnana Shakti and kriya Shakti)
28. In Japanese culture, the Three Treasures are, Mirror, Sword and Jewel–that being Truth, Courage and Compassion.
29. Nobel peace medal – The reverse side of the Nobel peace medal shows three naked men embracing one another – a symbol of the international fraternization that Nobel wished to contribute to through the Peace Prize. The inscription is in Latin: Pro pace et fraternitate gentium (For peace and fraternity among peoples).
30. Primary Colours – Only three primary colours are needed to mix most other colours; red, yellow and blue.
31. Lies -According to Benjamin Disraeli (British Prime Minister, 1804-1881) there are three degrees of lies: Lies – Damned Lies – Statistics
32. Troika – The word “troika” is a Russian word for threesome, triplet or trio. A Troika is three-horse harnessed sledge. Troika is also the name of a traditional Russian dance. The dancers dance in groups of three. A Troika also means a committee consisting of three members. During the rule of Stalin, the Troika was used to speed up the prosecutions of people accused of political crimes. In that meaning a Troika consisted of three judges and replaced the normal legal system.
33. Three Grains – An old superstition from Britain states that it is lucky to find three whole grains in a loaf of bread. Another bread superstition says it if you take three loaves of bread out of the oven at one time, a death of someone you know will occur within a year.
34. Tri- means three. So triangles have three sides, tripods have three legs and the dinosaur triceratops had three horns. The French and the Indian flags are called tricolour flags because it has three colours. Trigonometry is a branch of mathematics based on measuring triangles.
35. Three-dimensional means that something has length, width and depth.
36. In Hindu philosophy number three represents AUM (OM) in its diagrammatic aspect which is considered to be primordial.
37. Number three is considered as a highly sacred number that represents the Trinal Lords Brahma, Vishnu, Maheshwara and their energies Saraswathi, Lakshmi and Paarvathi. Known as Trimoorthi (Trinity) they are highly revered in Hindu philosophy.
38. Sacred Yagnopaveetham is the triple stranded sacrificial thread joined by a knot called Brahmagranthi that is worn by those initiated into the Gaayathri recital.
39. Triguna – There are three states of mind or three natures or three temperaments that rule the behaviours of humans viz. Saatvika (humble and peace loving), Raajasa (aggressive) and Taamasa (inertia ridden).
40. Tridalam-Trigunaakaram –Sacred Bilva pathra used especially in the worship of Lord Shiva is a confluence of three leaves trifoliate, which is a symbolic representation of Lord Shiva’s weapon Trident (Trishoola). It represents the Trinal Lords Brahma, Vishnu and Maheshwara. It also represents the three qualities Sattva, Rajo and Tamo gunas and a symbolic representation of three syllables of Omkaara. Bilva dala also represents the three eyes of Lord Shiva who is known as Trinethra.