If the diameter of the circle is 17.4 cm, the approximate circumference of the circle would be 54.636. If the radius of the circle is 17.4 cm, the approximate circumference would be 109.272.
Explanation: Circumference of a circle = Pi (3.14) x diameter
In this case, the diameter (I am assuming) is 17.4, so in order to solve the circumference you must multiply Pi by 17.4.
(If 17.4 is the radius, simple multiply 17.4 by 2 and then solve for the circumference like you normally would. You must multiply the radius by two because the radius is half of the circles circumference.
I'm pretty sure the answer is "A matrix separates rational and irrational numbers." (Note: I'm not that great with memorizing definitions, but I'm pretty sure.) Hope this helps :)
