I need the area of ABC but don't know how to get the base.

Base=Width x Length

if you are finding this for a triangle, then it is 1/2 Width x Length

From my viewpoint; your length is 4 and your width is 5, so your base should be 20 units

(sorry if this isn't complete; I was having some trouble understanding the full question)

if the printer produces 6 pages in 6 seconds it would be 1 page per second.

mathematically: 6 pages/6 seconds= 1 page/second