Final answer:
To calculate the radius of a circle given its area, divide the area by π and take the square root of the result.
Step-by-step explanation:
To calculate the radius of a circle, we can use the formula for the area of a circle: A = πr². Since the area is given as 86 cm², we can rearrange the formula to find the radius: r = √(A/π). Plugging in the given area, we get r = √(86/3.14159) ≈ 5.2 cm. Therefore, the radius of the circle is approximately 5.2 cm.