Someone please help me determine if the following sets are closed under the given operation/ help me by showing work as well justify answer? M=[all numbers of the form 2^n, for natural numbers] under addition?

N=[all numbers of the form 2^n, for n natural number] under multiplication?​

An observer(o) spots a plane(p) taking off from a local airport and flying at a 29 degree angle horizontal to her line of sight and located directly above a tower(t). the observer also notices a bird circling directly above her. if the distance from the plane(p) to the tower(t) is 6,000ft., how far is the bird(b) from the plane(p).