Answer:
Option C is correct.
The perimeter of the regular pentagon is, 10 cm
Step-by-step explanation:
The formula for the area of n-sided regular polygon is given by;
......[1]; where s is the length of the side and n is the number of side .
Given: Area of regular pentagon is 6.9 square cm.
Here, n =5
to find s;
Substitute the value of A and n in equation [1];

or

or

Taking both side square root, we have;

Simplify:
s = 2.00263 cm
or
s ≈ 2.00 cm
Therefore, the side of the length of regular pentagon is, s≈ 2.00 cm
Now, to find the perimeter of regular pentagon;
Use the formula:
Perimeter of regular pentagon(P) =
where s is the side.
Substitute the value of s≈ 2.00 cm.
P =
cm
therefore, the perimeter of the regular pentagon is; 10 cm