How to pronounce “right triangle” in English

What Archimedes proved was that the area of a circle is the same as the area of a right triangle with height

says that d, the distance you've moved, is the hypotenuse of a right triangle.

And as a result, the photon's trajectory, my photon's trajectory is straight, and it follows the hypotenuse of a right triangle.

I say, Pythagoras's theorem says the sum of the squares of the two sides of the right triangle equals the square the hypotenuse.

You may know you can have a 3, 4, 5, right triangle.