Perimeter means the sum of length of all sides of a figure. In case of a circle the perimeter is termed as a circumference.
Here in the given figure it can be noticed that there are four sides.
Two of its side equals 10in and the other two are 3in.
Summing all them up:
10 + 10 + 3 + 3 = 26in
Therefore the perimeter of the figure is 26in.
Hope it helps ^_^