This question can simply be answered directly. To solve
this, we should recall that the formula of a circle is:
Area of circle = π r^2 where
r is the radius of the circle
Now we are given that segment OA is equivalent to 5 units.
Segment OA is also the diameter of that circle therefore d = 5.
Now let us convert the formula knowing that radius is one
half the diameter:
r = d / 2
Area of circle = π (d / 2)^2
Area of circle = π d^2 / 4
Substituting:
Area of circle = π (5)^2 / 4
Area of circle = 3.14 * 25 / 4
Area of circle = 19.625 = 19.6 square units
