a square, rectangle, diamond..........
four, one for each corner. If a corner is not a right angle, the shape is then called a rhombus.
"Diagonal" is not a shape, it is a direction, or orientation. If you drew a line from one corner of a square to the opposite corner, that new line would be diagonal to the square. Here is an example: / or \
It will have an L shape flipped around at the corner. or you can use a protractor or type in google images 'right angle triangle' they will have an L shape at the corner of the right angled triangle.
They are called a Vertices and it is where 2 edges meet.
It is possible, but not always true.
A quadrilateral.
square
It cannot be a polyhedron nor any "normal" 3d shape.
A square with a rounded corner. =)
Many 3d shapes have a corner.
A shape with one corner is a triangle. Yes, I know, technically it has three sides, but it only has one corner. So, there you have it, a triangle is the shape you're looking for.
Wich 3 D shape has a corner on it?
triangle
A teardrop shape?
A diagonal.
The corner on a shape where edges meet is called a vertex.
Any polyhedron.