The triangles are (bh)÷2 = (3•4)÷2=6 There are 4 triangles so 6•4=24. Your missing side length of the triangle is 5 so the area of the parallelogram is 4.33 since 1 isn't exactly the height. There are 4 parallelograms so multiply by 4. 4.33 times 4 equals 17.32. Now add that area to the triangles and get:
17.32+24=41.32
There area of the whole figure is 41.32.
Hoped I helped!