In order to find the shaded region the first thing you have to do is find the area of the two small triangles, then find the area of the big triangle. Subtract the area of the small triangles from the big one and that is the area.
Step one: 11×12=132
Step two: 132÷2= 66
Step three: 66+66=132 (because there is two small triangles with same dimensions)
Step four: 40×15=300
Step five: 300-132=168
Answer 168m^2
