Answer:
82cm squared
Explanation:
1. Find the area of the whole rectangle.
(3+4)x(3+10)
7x13=91
2. find the area of the triangles together
Dimensions of both triangles 3 and 3
3x3=9
Divide by 2 because this is a triangle, not a rectangle
9/2=4.5
Do the same for the other triangle because they are the same size (3x3=9 9/2=4.5)
Add the area of the triangles together.
4.5+4.5=9
3. Subtract the area of the triangles from the area of the full rectangle
91-9=82cm squared