a meeting point of two lines that form an angle; a corner.
The point where two lines form an angle is called the vertex.
It is important to know terminology when learning math. The Vertex is the point where two lines meet and form and angle.
Two lines that form a right angle at their point of intersection is called perpendicular lines.
Perpendicular lines intersect and form a right angle. The lines on a square are perpendicular to each line that it touches.
Two perpendicular lines form right angles at their point of intersection.
a quadrilateral where each angle is a right angle
That's the "vertex" of the angle.
It is an indicator that the angle formed at that point is a right angle (90 degrees).The small square at the crossing point of two perpendicular lines serves to indicate that the two lines indeed form an angle of 90 degrees.
They are perpendicular to each other.