A triangle, but only if the line segments are straight.
right triangle
triangular polygon
The term 'equilateral' means having equal sides. For example, an equilateral triangle is a triangle with 3 sides all of equal length.
The abbreviation for triangle is "tri." In geometry, the term "tri" is commonly used to represent a triangle in equations, diagrams, and proofs. It is derived from the prefix "tri-" which means three, reflecting the three sides of a triangle.
There is no specific name in general. If the line segments are straight, then it is a triangle.
That figure is best described as a "triangle".
A triangle, but only if the line segments are straight.
The term "Bermuda Triangle" was popularized in the 1960s to describe the area in the western part of the North Atlantic Ocean where several aircraft and ships have disappeared under mysterious circumstances. The shape of a triangle was chosen to represent the geographic boundaries of this area. There is no particular reason why it is not called a circle, it was just a choice made by those who coined the term.
There is no synonym. Mathematics uses very specific words for fundamental terms.
One term often used is a URL (uniform resource locator).
The Nth term for a triangle number is: 0.5n(n+1)
The term for a large rounded articulating knob is "lunate."
A triangle is a 3 sided polygon
There really isn't a specific term to that matter. They're just called ends.
The answer depends on what you mean by "mean of triangle". There is no such geometric term.
The general term is trigonometry. What specific formula you use depends on what other information you have.