Of all the connecting lines between a point on a straight line and a point outside the straight line, the vertical line segment is the shortest.
Other line segments are called diagonals.
The diagonal part is larger than the vertical part.
In a right-angled triangle, it can be understood that the hypotenuse is larger than the right-angled side (the diagonal segment is the hypotenuse and the vertical segment is one of the right-angled sides).