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
This is not answer but Photomath is really helpful and it shows you step by step on how to solve it as well
Tan 42 = 12.5/x
x = 12.5 /tan 42
x =13.88