Beyond Right Triangles
The relationship between the squares of triangle sides tells you about the triangle's angle types. This extension of the Pythagorean concept helps classify triangles.
For right triangles, the equation a² + b² = c² holds true. For example, a triangle with sides 5, 12, and 13 is right because 5² + 12² = 13² (25 + 144 = 169).
In obtuse triangles, the square of the longest side is greater than the sum of squares of the other two sides: a² + b² < c². A triangle with sides 5, 6, and 10 is obtuse because 5² + 6² < 10² (61 < 100).
For acute triangles, the square of the longest side is less than the sum of squares of the other two sides: a² + b² > c². A triangle with sides 7, 10, and 11 is acute because 7² + 10² > 11² (149 > 121).
⚠️ Important note: Before applying these rules, remember to check if the sides can actually form a triangle at all! The sum of the lengths of any two sides must be greater than the third side.