Answer:
It looks like you might be referring to the Pythagorean Theorem. The Pythagorean Theorem is a fundamental principle in geometry that is applied to right-angled triangles. It states that in a right-angled triangle, the square of the length of the hypotenuse (the side opposite the right angle) is equal to the sum of the squares of the lengths of the other two sides. Mathematically, this is expressed as:
\[ c^2 = a^2 + b^2 \]
where:
- \( c \) is the length of the hypotenuse,
- \( a \) and \( b \) are the lengths of the other two sides.
The Pythagorean Theorem is applicable only to right-angled triangles because it relies on the specific properties of the 90-degree angle to establish this relationship between the sides.