Pythagorean triples are 3 whole numbers which satisfy the Pythagorean theorem when they make up the sides of a right angled triangle.
For the numbers 3, 4 and 5, let 5 be the length of the hypotenuse (AC, of triangle ABC in which B is a right angle), and 4 and 3 be the lengths of the other 2 sides of the triangle (AB and AC).
According to the Pythagorean theorem,
=
25 = 9 + 16
25 = 25
Since 3, 4 and 5 satisfy the criteria, they are Pythagorean triples.
Similarly, for the numbers 8, 15 and 17, let 17 be the length of the hypotenuse (PR, of triangle PQR in which Q is a right angle), and 4 and 3 be the lengths of the other 2 sides of the triangle (PQ and QR).
289 = 225 + 64
289 = 289
Since 8, 15 and 17 satisfy the criteria, they are also Pythagorean triples.