If the area of a circle is 154 cm², then its circumference is

Let r be the radius of the circle.

It is known that, area of a circle = π × (radius)²

It is given that, area of the circle = 154 cm²

∴ π r² = 154 cm²

$$\begin{gathered} \Rightarrow \frac{22}{7}{r}^2=154 \\ \Rightarrow r^2=49 \\ \Rightarrow r=7 cm \end{gathered}$$

Circumference of the circle = 2π × radius = $2\times \frac{22}{7}\times 7$ = 44 cm 

Thus, the circumference of the given circle is 44 cm.