Answer:
31
Explanation:
Multiply 7•2 which is 14, then multiply that by 2 so 14•2 because the sides are symmetrical, and that would be 28. After that you subtract 7-(3+3) to get the length of the center piece, and that would be 1, and multiply that by 3 which is 3. After that you add 28+3 and that's 31