Answer: The answer is (b) 20 sq. cm.
Step-by-step explanation: As given in the question and shown in the attached figure, ABC is a right-angled triangle with ∠ABC = 90°, the legs AB = 4√2 cm and BC = 5√2 cm.
We are to calculate the area of ΔABC.
Since AB is perpendicular to BC, so AB will be height and BC will be the base of the triangle.
Therefore, area of ΔABC is
[tex]a=\dfrac{1}{2}\times AB\times BC=\dfrac{1}{2}\times 4\sqrt 2\times 5\sqrt 2=20~\textup{sq. cm.}[/tex]
Thus, the correct option is (b) 20 sq. cm.
