Rebekah found 28 seashells can she share them equally among the 6 people in her family

Astick 2 m long is placed vertically at point b. the top of the stick is in line with the top of a tree as seen from point a, which is 3 m from the stick and 30 m from the tree. how tall is the tree?

How many sides does a regular polygon have if each exterior angle measure is 45 degrees explain your answer, i really don't understand this.

Plz ( true - false) all triangles have interior angles whose measure sum to 90.