uml - Understanding why the extends arrow points in the opposite direction - Stack Overflow

In class diagrams I typically see something like ClassA extends ClassB where the arrow head points to ClassA. Example, here. This has always confused me. Why is the arrow head not pointing to ClassB?

Planet SIPB

Class diagram - Wikipedia

uml - Understanding why the extends arrow points in the opposite direction - Stack Overflow

MUPPIT: a method for using proper patterns in model transformations

oop - UML inheritance - why is the direction of arrow from the subclass to the parent-class? - Stack Overflow

OOAD - Quick Guide

US7576876B2 - Relay device for relaying data from a sensing device to a computer system - Google Patents

2.5.13 Database Design Techniques and Deliverables

UML Class Diagram Arrows overlap when we add new nodes to existing diagram - GoJS - Northwoods Software

Direction of the association arrow in UML class diagrams - Stack Overflow