Answer:
Step-by-step explanation:
From the diagram in the image attached:
Base of triangle = [tex]20cm - ( 4 + 3)cm[/tex]
Base of triangle = [tex]20 - 7 = 13cm[/tex]
Height = 9cm
Area of triangle = (0.5) × base × height
Area of triangle = [tex]0.5 \times 13 \times 9 = 58.5cm^2[/tex]
Area of rectangle = Length × width
Area of rectangle = [tex]20 \times 9 = 180[/tex]
Shaded area = area of rectangle - area of triangle
Shaded area = [tex]180cm^2 - 58.5cm^2[/tex]
Shaded area = [tex]121.5cm^2[/tex]