The area of a triangle can be found by using the formula A = bh/2
To find the area of the shaded region (the green section), we can find the area of both triangles and subtract.
Large triangle:
A = 28*36/2
A = 1008/2
A = 504km²
Small triangle:
A = 15*19/2
A = 285/2
A = 142.5km²
Subtract both triangles:
504 - 142.5 = 361.5km²
Therefore, the area of the shaded region is 361.5km²
Best of Luck!