Answer:
9 units²
Step-by-step explanation:
calculate the area of Δ ABC as
area of rectangle - area of 3 outer right triangles
area of rectangle = 5 × 4 = 20 units²
area of left Δ = [tex]\frac{1}{2}[/tex] × 3 × 3 = 4 [tex]\frac{1}{2}[/tex] units²
area of Δ on right = [tex]\frac{1}{2}[/tex] × 2 × 4 = 4 units²
area of top Δ = [tex]\frac{1}{2}[/tex] × 5 × 1 = 2[tex]\frac{1}{2}[/tex] units²
Then
area of Δ ABC = 20 - 4 [tex]\frac{1}{2}[/tex] - 4 - 2 [tex]\frac{1}{2}[/tex] = 20 - 11 = 9 units²
