What is the meaning of a perimeter of triangle?
The ‘perimeter’ of any closed figure drawn on paper means the total distance around it. If the figure consists of straight lines, then the perimeter is the sum of the lengths of all the straight-line pieces. If you set an ant down at a certain point on the figure and he started walking along the line, the perimeter is the distance he would have to walk in order to wind up at the point where he started.