Define angle of friction and angle of repose?

Question: Define angle of friction and angle of repose?

The main difference between angle of friction and angle of repose the angle of friction is define as the angle between the normal reaction force and the resultant force of normal reaction force and friction when object just begins to move, where as the angle of repose as the minimum angle of it inclined plane which cause an object to slide down the plane. the angle of repose also has use in soil mechanics.