If JM = 4 & JK = 9, find LK

Question

I need help with solving this question as well as the first one! 

Answer 1

jm = 4, jk = 9

if j is in the middle of a line

then mk = 4+9=13

odds are you meant to ask what is mk, not lk

if J is a 90 degree angle formed by jm and jk

then mk = sqr(4^2+ 9^2) = sqr97= almost 10

5 < mk < 13

regardless of what angle J may be