BTH-G6- Angles and Constructions

What do these three angles add to?

What do these three angles in this picture add to?

The two marked angles are equal.

What is the size of one of the marked angles?

Each of these angles is the same size.

What is the size of each angle?

Work out the size of the unknown angle in this non-convex quadrilateral.

(Non-convex - if one or more of the interior angles is more than 180 degrees.)

Four angles, all the same size, combine to form a complete revolution.

What is the size of each angle?