To calculate the perimeter of a shape, like this window, you can add the length of all the sides together. 100cm + 120cm + 100cm +120cm = 440cm Or, you can multiply the length and width by 2. You ...

GCSE OCR 2-dimensional shapes - OCR Perimeter 2-dimensional shapes are flat. The perimeter of a 2D shape is the total distance around the outside of the shape.