Its the first one, 22.5. This is because... if you multiply 5 and 4, you would get 20, the area of the square. You then have to multiply 1 and 5 to get 5 and divide it by 2 to get the area of the triangle which would be 2.5, then add 2.5 to 20 and get 22.5.
Hope this helps :)