Multiply each of the diameters by pi (pi = 3.14159265 or 3.14 for rough approximation) to find the circumferences of the circles.
You need only know the radius of each circle to determine that they are congruent. If the radii are identical, the circles are identical. This can also be determined by comparing the diameters (twice the radii), or the circumferences, or the areas of the circles. In all cases, if the parameters are identical, the circles are identical.
They are its circumferences
There are infinite amount of diameters.
d = 9.55 cm
Their circumferences are in the same ratio as their diameters.
Because it was found that there was a direct relationship between the radii (or diameters) of circles and their circumferences.
Multiply each of the diameters by pi (pi = 3.14159265 or 3.14 for rough approximation) to find the circumferences of the circles.
Their radii, diameters or circumferences - in all three cases the ratio between the axle and wheel are the same.
The answer depends on whether the two measures given are radii or diameters and also whether the differences in question are in their circumferences or areas.
The perimeter of a circle
They are circumferences
An arc
You need only know the radius of each circle to determine that they are congruent. If the radii are identical, the circles are identical. This can also be determined by comparing the diameters (twice the radii), or the circumferences, or the areas of the circles. In all cases, if the parameters are identical, the circles are identical.
It is the planet's diameter multiplied by pi
They are its circumferences
There are infinite amount of diameters.