It is called a diagonal.
straight angle
the measure of a straight-line distance between two points is called length.
Vertexes, vertices, or corners.
The corners are called vertices which is the plural of vertex
It is a 5 sided pentagon that has 5 corners which are called vertices.
The opposite of vibrato in music is called straight tone.
is called a straight angle
straight angle
A line is a straight path that extends infinitely or endlessly in opposite directions. A straight path that joins two points is called a line segment.
straight angle
Oh honey, an angle formed by opposite rays is a straight angle. It's like a perfectly straight line, no curves or funny business. So if you see those opposite rays coming together, you better believe they're forming a straight angle, no ifs, ands, or buts about it.
It is called a line segement
In some English dialects, gay men were referred to as "bent," making "straight" a reasonable opposite.
Corners
A straight angle.
If, by square corners, you mean corners that are right angles, then any polygon with four or more sides can have two square corners. Furthermore, apart from near the corners, the lines need even be straight so the shape need not be a polygon. In the limit a semicircle has two right angles.
the measure of a straight-line distance between two points is called length.