70 cm²
1) Examining the figure we can decompose that polygon into
triangles
trapezoids
rectangle
2) So we can see that in here:
Now we can calculate the area
Trapezoids:
There are 2 trapezoids so 16cm²
Rectangle:
S = w*l
S= 3 *12 = 36 cm²
Triangle:
S= 1/2(b*h)
S = 1/2(36)
S= 18 cm²
We have two triangles so =
3) So the answer is
16cm² + 18cm² + 36cm²=70cm²