Answer:
3cm
Explanation:
Perimeter is the boundary or outer line of a shape
Rectangle has 4 sides.
2 sides of top and bottom, being the same size
And 2 sides of left and right sides being the same size.
Perimeter of Rectangle = 9+5+9+5 = 28
Regular Pentagon has 5 equal sides.
So perimeter is: 5+5+5+5+5 = 25
Difference is biggest take away smallest
Therefore 28-25 = 3
Answer = 3cm