Chapter 5.5, Problem 29E

Recall (lie Pythagorean theorem from geometry: If a right triangle has legs of lengths a and b and hypotenuse of length c, then

$a^2+b^2=c^2$

Suppose that we choose any four successive terms of the Fibonacci sequence. Multiply the first and fourth. Double the product of the second and third. Add the squares of the second and third. The three results obtained form a Pythagorean triple (three numbers that satisfy the equation $a^2+b^2=c^2$

). Find the Pythagorean triple obtained this way, using the four given successive terms of the Fibonacci sequence.

5,8, 13.21