The answer depends on what the 19.4 km refers to: the radius, the circumference or something else. Since you have not bothered to share that crucial bit of information, I cannot provide a more useful answer.
A circle with a radius of 0.9 km has an area of 2.54 square km
Circumference = pi*diameter = 5.65 km, approx.
radius = 48/2 = 24 km
half of d
To convert 8 kilometers into diameter, it depends on the context, as diameter typically refers to a circular measurement. If you mean a circle with a diameter of 8 km, then the diameter is simply 8 km. If you're referring to the circumference of a circle, you can use the formula (C = \pi d) to find the diameter, but you'd need to know the circumference in this case.
The circumference of a circle with a diameter of 16 km is: 50.3 km
Then it will have a diameter of 16 km
A circle with a radius of 0.9 km has an area of 2.54 square km
circumference of a circle = pi*diameter
The circumference of a circle with diameter of 3,000,908,987,656 cm is94,276,336.30142 Km (rounded)
9.4 km
Circumference = pi*diameter = 5.65 km, approx.
radius = 48/2 = 24 km
half of d
the radius of a circle is half the diameter, so half of 1.8 is .9. The radius is .9km.
To convert 8 kilometers into diameter, it depends on the context, as diameter typically refers to a circular measurement. If you mean a circle with a diameter of 8 km, then the diameter is simply 8 km. If you're referring to the circumference of a circle, you can use the formula (C = \pi d) to find the diameter, but you'd need to know the circumference in this case.
It would be 2.5434 km2.