Theory:

What is the perimeter of the combined shape?
 
The perimeter of the combined shape is same just like finding the perimeter of other shapes. The perimeter of the combined shape is the sum of all the outer sides of the given shape.
Example:
Let us consider an example to understand the concept clearly.
 
15.png
 
To find the perimeter, let us add all the outer measures of the given shape.
 
Perimeter \(=\) Sum of all measures of outer length
 
Perimeter \(=\) \((12+1+1+6+6+3+3+6+6+6)\) \(cm\)
 
Perimeter \(=\) \(50\) \(cm\)
 
Therefore, the perimeter of the given combined shape is \(50\) \(cm\).