IIIF provides researchers rich metadata and media viewing options for comparison of works across cultural heritage collections. Visit the IIIF page to learn more. This model of a part of a hinged ...

Now use the information you already have about finding the equation of a line and apply it to the dashed lines shown in these triangles. Remember, to find the equation of a line you need a point ...

The Monthly publishes articles, as well as notes and other features, about mathematics and the profession. Its readers span a broad spectrum of mathematical interests, and include professional ...

To illustrate the Pythagorean Theorem, makers of geometric models have long made models with pieces that could be arranged either as a square with a side equal to the length of the hypotenuse of a ...

The six intersection points of a triangle’s non-parallel altitudes and perpendicular bisectors are the vertices of two congruent minor periambic triangles which are inversely similar to the original.

In the diagram below, AB is the chord of a circle with centre O. OM is perpendicular to AB (meet at a right angle). Look at triangles OAM and OBM. The hypotenuses (OA and OB) are the same, as they are ...