Answer:
123.5 m^2
Step-by-step explanation:
The area of the whole rectangle is 9 x 19 = 171 m^2
The area of the region that isn't shaded is (5 x 19)/2 = 47.5 m^2 because the height of the triangle is 5 (9 - 4) and the area of a triangle is
(height x length)/2
171 - 47.5 = 123.5 m^2
