Answer:306
Step-by-step explanation:
since the width of the bottom square is 10, you split it between the triangles on top. You have to do this because 7 is not the whole width of the two triangles. So then the width of the triangles would be 12, 12 times 9 is 108, you'd have 216 total for both triangles and then the area of the square is 90, 90 plus 216 is 306.
