Lines and Angle...

In figure, $$POR$$ is a line. The value of $$a$$ is 

The difference of two complementary angles is $$30^o$$. Then, the angles are:

In figure, $$a$$ and $$b$$ are :

In figure, $$\angle AOC$$ and $$\angle BOC$$ form a pair of 

In which of the following figures, $$a$$ and $$b$$ are forming a pair of adjacent angles?

In figure, the value of $$a$$ is 

In figure, lines $$PQ$$ and $$ST$$ intersect at $$O$$. If $$\angle POR=90^o$$ and $$x:y =3:2$$, then $$z$$ is equal to 

In figure, which one of the following is not true ?

In figure, $$a=40^o$$. The value of $$b$$ is 

In figure, which of the following is true?