Answer:
18 units²
Step-by-step explanation:
there are two ways to calculate the required area.
way 1.
the length of the side AB=7+2=9; the length of CD is 6-2=4 (note, CD⊥AC), then the required area is:
A=9*4/2=18.
way 2.
the coordinates of the vector AB=(0;-9), of vector AC=(4;-3).
The required area can be calculated using the formula: A=0.5*[ABxAC].
[tex]|A|=|\frac{1}{2}*\left[\begin{array}{ccc}0&-9\\4&-3\\\end{array}\right]|=|(-36):2|=18.[/tex]
