Find x.
44∘
55∘
66∘
77∘
By exterior angle property, x + 58∘ = 124∘ x = 124∘ - 58∘ x = 66∘
3^a = 4
4^b = 5
5^c = 6
6^d = 7
7^e = 8
8^f = 9
then abcdef = ?