As shown in the figures given :
For Figure 1 : perimeter = 8 units [As can be seen in the figure]
For figure 2(with 2 octagons) : perimeter = 8 × 2 - 1 = 15 units [since 1 side is common ]
For figure 2(with 3 octagons) : perimeter = 8 × 3 - 2 = 22 units [since 2 sides is common ]
If one more octagon is added
then perimeter = 8 × 4 - 3 = 29 units [since 3 sides will be common ]
The perimeter of the equilateral triangle will be 76.2 in
<u>Explanation:</u>
Altitude of an equilateral triangle, H = 22 in
Perimeter, p = ?
Let a be the side of the triangle
We know:

Perimeter = 3a
P = 3 X 25.4 in
P = 76.2 in
The sum of the interior angles of a triangle is 180 degrees
2x-9+3x+x+3=180
6x-6=180
6x=186
x=31
A=2(31)-9
A=62-9
A=53
the answer is A because indont know 9bp