If the triangle had a right angle (90°), and you made a square on each of the three sides, then the biggest square had the exact same area as the other two squares put together.
It is called “Pythagoras Theorem” and can be written in one short equation: \(a^2 + b^2 = c^2\)
In a right angled triangle, the square of the hypotenuse is equal to the sum of the squares of the other two sides.
Let’s see if it really works using an example.
Pythagoras Theorem Example:
A “3,4,5” (pythagorean triple) triangle has a right angle in it.
Let’s check if the areas are the same:
\(3^2\) + \(4^2\) = \(5^2\)
Calculating this becomes:
9 + 16 = 25.
If we know the lengths of two sides of a right angled triangle, we can find the length of the third side. (But remember it only works on right angled triangles!)