A quadrangle is a closed figure that has the following attributes: 2-dimensional, 4 vertexes, 4 sides, and 4 angle
All angles are made up when two lines or sides vertexes or intersection points, I think.
Polygons have the same number of vertexes/vertices as the sides. So, A 20 sided polygon will have 20 vertexes/vertices.
two
Decagon
No.
A CIRCLE OR AN OVAL
It is simply a right angle triangle but if the sides were the same then it is an isoceles right angle triangle
In plane geometry, a shape with four sides, two of which are parallel and have the same length, cannot have a reflex angle.
cube
a triangle with two sides the same length and no right angle
Same as it is in any other angle ... the point where the sides of the angle join (or cross).