Answer:
126 cm squared
Explanation:
Let's draw a line to form a rectangle with a triangle on its side.
To find the area of the rectangle, we use the b * h area formula, where b is the base and h is the height. In this case, we know the base is 12 (so b = 12) and the height is 9 (so h = 9). Then, the area of the rectangle is 9 * 12 = 108 cm squared.
To find the area of the triangle, we need to use the (b * h)/2 area formula, where b is the base and h is the height. We know that the entire length is 12, and that the two sides next to the triangle base are each 3. So, the triangle base would just be 12 - 3 - 3 = 12 - 6 = 6 cm. So, b = 6.
Now, to find the height of the triangle, we see that dotted line is the entire height of both the triangle and the rectangle. The total is 15, and the rectangle's height is 9. To get the triangle's height, we simply subtract 9 from 15: 15 - 9 = 6. So, h = 6.
Then, the area of the triangle is (6 * 6)/2 = 36/2 = 18 cm squared.
The total area is the sum of the triangle area and rectangle area:
18 + 108 = 126 cm squared, which is the answer.
Hope this helps!