Help me ASAP with all the problems and step by step of how you got the answer

Which two undefined geometric terms always describe figures with no beginning or end?

In triangle △abc, ∠abc=90°, bh is an altitude. find the missing lengths. ac=26 and ch=8, find bh.

Let d be the domain and let ƒ be the possible function. determine if the relation is an example of a function. d = {x| x is a date, expressed in day/month/year} ƒ(x) = temperature in seattle washington on that date