Some mathematical theorems don't just prove a statement to be true, but they reveal something beautiful that itches our intuition. Viviani's Theorem is one of those rare gems. The theorem says something profound but geometrically elegant:

For any point inside an equilateral triangle, the sum of the perpendicular distances from that point to the triangle's three sides is always equal to the height of the triangle.

Take the equilateral triangle below as an example:

By picking any point P, we can draw lines perpendicular to each edge of the triangle that touch point P. The length of these lines always add to 6, which we will discover is the height of this triangle.

To explore this more, former Maplesoft co-op student Michael Barnett made a Maple Learn document on Viviani's Theorem where this is seen in action, as shown below.

No matter where the point P moves, the sum of perpendicular distances from that point to the edges of the triangle always add to the same value: the height of the triangle.

To see why this is the case mathematically, consider the example from before:

More generally, if we let x, y, and z be the shortest distances from the point P inside the triangle to the sides AB, AC and BC, respectively, one can conclude that:

In words, the sum of these distances x+y+z is simply the height of the triangle, h, no matter where the point P lies inside the triangle.

Even after reading this proof, it may be tempting to think of cases where this would not be true. I like to think of Maple Learn as a playground for geometry, algebra and visualization to interact. It helps to convince us that even for many different cases (in fact, all cases!), this theorem holds true.

Viviani's Theorem is a reminder that mathematics isn't always about answers. Instead, it's about finding hidden harmonies that our intuition begs us to question and search for. With tools like Maple Learn, those harmonies buried in symbols and complicated definitions can be uncovered and explored.

If geometry ever felt too distant or abstract, this is your invitation to see it come alive!