The perimeter of this rectangle is in dark green.
The perimeter of a square or a triangle is the distance all the way around the edge – the green strip in this picture.
The circumference of a circle is also its perimeter. The perimeter of a quadrilateral, like a square or a rectangle, is always equal to twice the length plus twice the width. The perimeter of a triangle or a hexagon is always equal to adding the length of all the sides together.
