In mathematics, a unit circle is a circle of unit radius—that is, a radius of 1. Frequently, especially in trigonometry, the unit circle is the circle of radius 1 centered at the origin (0, 0) in the Cartesian coordinate system in the Euclidean plane.
Answer:
Step-by-step explanation: pi r^2
so 42/2 equals 21 radius
volume=22/7 x 21^2
v=1385
Answer:
r
Step-by-step explanation:
50,000 is the nearest ten thousand.