Given the area of a circle A = 154 cm2. We will use pi = (22)/(7).

The formula for the area of a circle is $A = \pi r^2$.

$$154 = \frac{22}{7} r^2$$

To find $r^2$, multiply both sides by $\frac{7}{22}$:

$$r^2 = 154 \times \frac{7}{22}$$ $$r^2 = 7 \times 7$$ $$r^2 = 49$$

Take the square root of both sides to find $r$:

$$r = \sqrt{49}$$ $$r = \boxed{\text{7 cm}}$$

The diameter is twice the radius: $d = 2r$.

$$d = 2 \times 7 \text{ cm}$$ $$d = \boxed{\text{14 cm}}$$

The formula for the circumference of a circle is $C = 2\pi r$ or $C = \pi d$. Using $C = \pi d$:

$$C = \frac{22}{7} \times 14 \text{ cm}$$ $$C = 22 \times 2 \text{ cm}$$ $$C = \boxed{\text{44 cm}}$$