Easy,
now it looks tricky but it's not,
you're trying to find the Area of the circle, but you don't have the radius.
What you do have is a triangle with two sides labeled [tex] \sqrt{2} [/tex]
Now, using Pythagorean Theorem:
[tex]a ^{2}+ b^{2}= c^{2} [/tex]
[tex] \sqrt{2} ^{2} + \sqrt{2} ^{2}= c^{2} [/tex]
But we know that the OPPOSITE of square root is squared.
Making it,
2+2=[tex] c^{2} [/tex]
4=[tex] c^{2} [/tex]
2=c
The third side is 2. (Diameter) As the radius, 1.
Now, to find the Area of a Circle,
A=[tex] \pi [/tex][tex] r^{2} [/tex]
A=[tex] \pi *1[/tex]
Making your answer, 3.14 sq cm, A.