also: テータ
noun
theta
The Greek letter Θ/θ, used as a symbol in mathematics, physics, and other sciences. Both readings シータ and テータ are used, with シータ being more common.
角度を表す変数としてθを使う。
We use θ as a variable to represent an angle.
この式のシータに数値を代入してください。
Please substitute a numerical value for theta in this formula.
Lowercase Greek letter theta; common in mathematics and physics.
From Greek θῆτα (thêta), via English 'theta'. The reading シータ reflects the Greek pronunciation, while テータ comes from the English pronunciation.