9) What is the variation, in the magnetic merdian swings like a pendulum in one direction for a long period and gradually comes to rest and then swings in the opposite direction?

10) What is the compass with the graduations are marked as south with 0 Degree and north with 180 Degree?

11) What is the direction indicated by an imaginary circle passing around the earth through the place north and south pole?

12) What is the compass that has graduation marked as 0 Degree on North and South and 90 Degree on East and West?

13) What is the sum of the interior angle of a pentagon?