A mathematical statement that contains an = sign is called an equation.
ex:
2x +5 is a statement, this is NOT an equation.
2x +5 = 10
this IS an equation, because it has an = sign.
i don't get the joke. kidding. an equilateral triangle
Well its still a 2d because its like a normal square
A triangle with 3 equal sides is an equilateral triangle. A triangle with 2 equal sides is an isosceles triangle. There is no such thing as a triangle with ONE equal side. Equal to what? If you wish to stretch it and say each side is (equal to itself only ) not equal to any others it is a scalene triangle.
There is no specific name, except in the case of a triangle: scalene. You should not call it simply an irregular polygon, because a regular polygon implies that ALL sides are equal and ALL angles are equal. So a rhombus, where all four sides are equal, is still irregular.
there's no such thing. "quad" means four, "lateral" means side. A quadrilateral must and always had only FOUR SIDES! however, a shape with three sides is a triangle.
a equation
An equation. (Both "equals" and "equation" have the Latin root aequatio.)
I don't know what a 'mathematical' sentence is. I'd prefer to call it an English sentence that describes a mathematical process and makes a statement concerning mathematical matters.
A strict inequality. The word "strict" is used to distinguish these from "greater than or equal to" and"less than or equal to".
This is a mathematical "expression".
you would call that an expression
There is no letter or symbol in the English language that contains an equal sing except the equal sign. There might be other languages that use the equal sign.
It's usually referred to as an "expression."
What do you mean by a "mathematical sentence"? In some practice in analysis (Calculus stuff), we call a statement a sentence if it looks like one or any combination of the following: "For all a in set A, condition P(a) is true/false" "There exist some (or unique) a in set A where P(a) is true/false" So in that practice, your statement is NOT a sentence, but if you phrase it "There exist a unique x in our set where x = 0 is true" or simply "There exist a unique element x where x = 0" It would be a sentence. BUT, I am pretty sure what I am talking about is not the same "mathematical sentence" as yours.
geometry
No, it is not a mathematical term.
Probability