From the information we have the diameter of the circle is 10 cm.
Area of a circle is given by 1/4π d²
A = 1/4 π d²
π = 3.14
d² = 10² = 100
So we now calculate.
A = 1/4 × 3.14 × 100
A = 0.25 × 3.14 ×100
A = 78.5 cm²
Using radius :
The radius of this circle is 10 ÷ 2 = 5
A = π r²
A = 3.14 × 5²
A = 3.14 ×25
A = 78.5 cm²
So we still get the same answer.