Explanation:
Instantaneous center:
It is the center about a body moves in planer motion.The velocity of Instantaneous center is zero and Instantaneous center can be lie out side or inside the body.About this center every particle of a body rotates.
From the diagram
Where these two lines will cut then it will the I-Center.Point A and B is moving perpendicular to the point I.
If we take three link link1,link2 and link3 then I center of these three link will be in one straight line It means that they will be co-linear.
