Vertical angles is the same angle, but we don't know "x". If you look in a way. We can do 180=(3x+80).
100=3x
100/3 = x
Now we have the answer for x we plug it in to get the answer.
3(100/3) + 80 =<D
<D = <C
9^0 its that answer because all the other number you can make a whole number.
68. add the two measures then subtract from 180.
8P4 is a permutation;
P(n,r) ; nPr = n!/(n-r)!
8P4 = 8!/(8-4)! = 40,320 / 4! = 40,320 / 24 = 1,680
The value of 8P4 is 1,680