The measures of the angles of △abc are given by the expressions in the table.

angle measure
a (4x−13)°
b 15°
c (x + 18)°
what are the measures of angles a and c?

enter your answers in the boxes.
m∠a=
º

m∠c=
º

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).