Pythagoras property
If a (hypotenuse), b (perpendicular) and c (base) are sides of a right angled triangle then the relation between them is always \[a^2+b^2=c^2\]
On the screen, we see a triangle ABC in red color. Angle A will always remain 90˚
Observe how the shape of the triangle ABC changes as we change the lengths of the sides AC (b) and AB (c) using their respective slide bars.