Final answer:
The area of the triangle is 126 square meters.
Step-by-step explanation:
The formula for finding the area of a triangle is 1/2 × base × height. To find the area of the triangle, you need to multiply the base and height and divide the product by 2. In this case, the base is 21 meters and the height is 12 meters. So, the area of the triangle would be:
Area = 1/2 × base × height
Area = 1/2 × 21 × 12
Area = 126 square meters