Illustration of a circle used to prove "Any angle inscribed in a semicircle is a right angle."

The lines of contact are equal, but the axes are neither parallel to each other, or the line of contact.

Still life arrangement including a globe, telescope, book, right angle, rolled map, and dividers.

Right triangle with squares that can be used to illustrate the Pythagorean Theorem.

Illustration of the resultant vector when two vectors are acting upon a body at point P at 90 degrees.