why is that when it comes to diagonal it must be divided into 2
When it comes to diagonals, it is because we typically consider diagonals in geometric shapes like squares or rectangles. Diagonals are line segments that connect two nonadjacent vertices of a polygon.
To understand why a diagonal is divided into two parts, consider a square. A square has four equal sides, and the diagonals are the line segments that connect opposite corners of the square. If you draw one of the diagonals, you will notice that it divides the square into two congruent right triangles. This is because the diagonal creates two equal halves, each of which is a mirror image of the other.
Similarly, in a rectangle, the diagonals divide it into two congruent right triangles. One diagonal connects two opposite corners, while the other diagonal connects the other two opposite corners. By drawing these diagonals, you can see that they split the rectangle into two equal halves.
In general, the reason why diagonals are divided into two parts is because they connect two nonadjacent vertices or corners of a polygon, creating equal halves on either side. This property holds true for many geometric shapes and is a fundamental concept in geometry.