Which of the following equations have the correct notation? check all that apply. (btw, most of my questions are from apex learning because i'm in summer school)

a. ba=4
b. ab=4
c. ab (with line over) =4
d. ba (with line over) =4

The point of intersection of the diagonals of a rectangle is 4 cm further away from the smaller side then from the larger side of the rectangle. the perimeter of the rectangle is equal to 56 cm. find the lengths of the sides of the rectangle. 16 points answer quick

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).

Aregular hexagonal pyramid has a base area of 45 in2 and a lateral area of 135in 2. what is the surface are are of the regular hexagonal pyramid