U+0398 "Θ" Greek Capital Letter Theta Unicode Character

U+0398 "Θ" Greek Capital Letter Theta is the eighth letter of the Greek alphabet, historically representing an aspirated "t" sound in classical Greek and later evolving into the voiceless dental fricative "th" in modern Greek, as in the English word "think." It is widely used in mathematics and science, often denoting an angle in geometry or trigonometry, a temperature variable in thermodynamics, and a parameter in statistics. In physics, it can represent the theta function or scattering angles, while in engineering and technology, it appears in symbolic notation for phases or thresholds. Its distinctive circular shape with a horizontal bar makes it a recognizable symbol in academic and technical contexts across many disciplines.