Because: two parallel black dots and a vertical black dot can be regarded as an inverted triangle.

So: two parallel black dots at the bottom and one black dot at the top can be regarded as a regular triangle.

Extended data:

Ryan was the first person to express "there" with symbols. In an algebra book 1659, he used two symbols "∴" and "⊙" to mean "so", among which "∴" was used more. The English version of the book 1668 also uses these two symbols to mean "so", but "∵" is used more. Jones uses ∴ in 1706 to mean "so". By the middle of18th century, "∵" was used to mean "so", at least as much as "∴". "

/kloc-at the beginning of the 0/8th century, no one used ∵ to mean "because". It was not until 1805 that \ u \ u \ u \ u \ u \ u \ u \ u \ u \ u \ u \ u \ u \ u \ u \ u \ u \ u \ u \ u \ u \ u \ u \ u \ u \ u \ u \ u \ u \ u \\ By 1827, Euclid's Elements of Geometry published by Cambridge University used ⊙ for "because" and ∴ for "so" respectively. This usage has become more and more popular and has been used ever since.

Symbolic meaning (meaning)

=? Equal to? be equal to

≠? Doesn't mean. unequal to

≈? About equal to? Approximately equal to

& lt？ Less than? less than

& gt？ Greater than? be more/bigger than

//? Parallel? Parallel to

⊥ Vertical

≥ greater than or equal to greater than or equal to

≤ less than or equal to less than or equal to

≡ Constant is equal to or congruent with.

π? Pi? About 3. 14 15926536 circumference to diameter ratio; circumference ratio

e？ Natural constant? The natural constant is about 2.7 1828 18285.

|x|？ Absolute value of x or absolute value of (complex) modulus

∽? Similar? be similar to

≌? Congruence? Equal to (especially for geometry)

Far greater than

& lt& lt is much less than

∪? Total sum

∩? intersection

Included in the

∈? belong to

⊙? circle

/division, quotient, is understood as divisibility in some programming languages.

α,β,γ,φ…? Angle; coefficient

∞ infinity (including positive infinity +∞ and negative infinity-∞)

Logarithm of lnx based on e (natural logarithm)

Logarithm of lgx based on 10 (common logarithms)

Lbx logarithm with base 2.

Lim seeks the limit

Floor(x) or [x] can also be written as

Rounding function (literally translated as "floor function"), also known as Gaussian function.

Ceil(x) can also be written as

Rounding function (literally translated as "upper bound function")

x？ mod？ Y module, find the remainder

X-floor(x) or {x} represents the fractional part of X.

Differential (or linear principal part) of dy, df(x) function y=f(x)

∫f(x)dx？ Indefinite integral, all primitive functions of function f

References:

Mathematical symbols-Baidu Encyclopedia