Answer: 120 cm².
Explanation:
 1. To solve this problem you must apply the formula for calculate the area of a triangle, which is:
 

 Where b is the base and h is the height of the triangle.
 2. Then, when you substitute the values given in the problem you obtain:
 

 3. You know that the shape is made of 12 right triangle of equal size, therefore, multiply the area obtained by 12.
 4. Then the area of the shape is:
 
