Find the area please and an explanation would be appreciated but its not demanded

186 is the answer, the explanation is: first you have to find the area of the box which is 162 because 18x9=162 then we have to find the triangle, we would find the area like a box 4x6=24 but we have to split it in half because a triangle is half a square so the area of the triangle would be 12. Making your answer 162+12=174