Answer:
24 Centimeters
Explanation:
what you want to do is split it up, make two triangles (the sides), and one big square. The square has the dimensions 4 by 4 which has the area of 16. The two triangles have the dimensions 2 by 4, which would be 4 and because there are two, the triangles equal 8. 16+8=24
Hope this helps. :)