Find missing angles when two or more polygons are joined

Maths

The diagram shows two hexagons joined. Calculate the size of the angle marked b.

A regular pentagon and a regular hexagon are joined. Calculate the size of angle a.

An octagon and a nonagon are joined. Calculate the size of the angle labelled g.

The sum of interior angles of a polygon is 720º. How many sides does the polygon have?

The sum of interior angles of a polygon is 2880º. How many sides does the polygon have?

The sum of interior angles of a regular polygon is 3960º. What is the size of each interior angle of the regular polygon?

The sum of interior angles of a regular polygon is 5040º. What is the size of each exterior angle of the regular polygon?