Answer:
9 units²
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 =
× 3 × 3 = 4
units²
area of Δ on right =
× 2 × 4 = 4 units²
area of top Δ =
× 5 × 1 = 2
units²
Then
area of Δ ABC = 20 - 4
- 4 - 2
= 20 - 11 = 9 units²