Of the three positive values: a + 1, 6a, and 6a + 1, 6a + 1 must be the largest.
Using the Pythagorean Theorem: (a + 1)2 + (6a)2 = (6a + 1)2
a2 + 2a + 1 + 36a2 = 36a2 + 12a + 1
a2 + 2a = 12a
a2 - 10a = 0
a(a - 10) = 0
Either a = 0 (impossible) or a = 10
