Pythagorean Triples

A "Pythagorean Triple" is a set of positive integers, a, b and c that fits the rule:

Example: The smallest Pythagorean Triple is 3, 4 and 5.

Calculating this becomes:

Yes, it is a Pythagorean Triple!

Triangles

When a triangle's sides are a Pythagorean Triple it is a right angled triangle.

Example: The Pythagorean Triple of 3, 4 and 5 makes a Right Angled Triangle:

triangle 3 4 5 lego

Here are two more Pythagorean Triples:

5, 12, 13 9, 40, 41
5 2 + 12 2 = 13 2 9 2 + 40 2 = 41 2
25 + 144 = 169 (try it yourself)

And each triangle has a right angle!

List of the First Few

Here is a list of the first few Pythagorean Triples (not including "scaled up" versions mentioned below):

(3, 4, 5) (5, 12, 13) (7, 24, 25) (8, 15, 17)
(9, 40, 41) (11, 60, 61) (12, 35, 37) (13, 84, 85)
(15,112,113) (16, 63, 65) (17,144,145) (19,180,181)
(20, 21, 29) (20, 99,101) (21,220,221) (23,264,265)
(24,143,145) (25,312,313) (27,364,365) (28, 45, 53)
(28,195,197) (29,420,421) (31,480,481) (32,255,257)
(33, 56, 65) (33,544,545) (35,612,613) (36, 77, 85)
(36,323,325) (37,684,685) . infinitely many more .

Scale Them Up

The simplest way to create further Pythagorean Triples is to scale up a set of triples.

Example: scale 3, 4, 5 by 2 gives 6, 8, 10

Which also fits the formula a 2 + b 2 = c 2 :

If you want to know more about them read Pythagorean Triples - Advanced

Useful

We can use these triples to make a right angle in the real world (such as with carpentry, tiling, etc)

The simple (3,4,5 triple) is the easiest to remember.

And if you need a triple with two nearly equal sides use (119,120,169) or (696,697,985).