I think it’s 10 girls, if wrong, message me I’ll correct it
The base is an equilateral triangle. The formula of the area of that triangle is:

a - length of side
a = 3". Substitute:

The lateral side is a rectangle.

The Total Area is equal the sum of two times of Base and three times of Lateral Side.

Associative property of addition.
This means that no matter where you put the parenthesis, you will get the same solution.
Hope this helps!