Answer:
A = 4 cm²
Step-by-step explanation:
The area of a triangle is calculated as
A = [tex]\frac{1}{2}[/tex] bh ( b is the base and h the perpendicular height )
b = AC = 3[tex]\sqrt{2}[/tex] + [tex]\sqrt{2}[/tex] = 4[tex]\sqrt{2}[/tex]
h = BD
Calculate BD using Pythagoras' identity in Δ ABD
BD² = AB² - AD²
= (2[tex]\sqrt{5}[/tex] )² - (3[tex]\sqrt{2}[/tex] )²
= 20 - 18 = 2 ( take square root of both sides )
BD = [tex]\sqrt{2}[/tex]
Then
A = [tex]\frac{1}{2}[/tex] × 4[tex]\sqrt{2}[/tex] × [tex]\sqrt{2}[/tex] = 2 × [tex]\sqrt{2}[/tex] × [tex]\sqrt{2}[/tex] = 4 cm²