What is the area of the circle shown in the illustration below?
a. 3.14 square centimeters
b. 6.28 square centimeters
c. 9.42 square centimeters
d. 12.56 square centimeters

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 

Now, using Pythagorean Theorem:





But we know that the OPPOSITE of square root is squared. 

Making it,

2+2=

4=

2=c

The third side is 2. (Diameter)  As the radius, 1.

Now, to find the Area of a Circle,

A=

A=

Making your answer, 3.14 sq cm, A.

A