I don’t know how to solve this

Answer:
see explanation
Step-by-step explanation:
The perimeter is the length of all the sides in the figure.
The arc of the semi- circle is included in this.
length of arc = [tex]\frac{1}{2}[/tex]πd ← d is the diameter
here d = 8, hence
arc = [tex]\frac{1}{2}[/tex]π × 8 = 4π ← exact length
Perimeter = 10 + 8 + 10 + 4π ≈ 40.57 in ( nearest hundredth )