Answer:
You break it up into smaller pieces! (48)
Explanation:
You can either take the area of the full rectangle, or of the square + 2 rectangles using length*width
3*12 = 36
You are left with the two triangles which area you can get using 1/2*width*height since they are right triangles.
1/2*4*3 = 6
36 + 12 = 48