I need help with basics of circles and just like how radius and circumference help and just how to remember it

Question

anonymous · Answer

how long did it take you to get 27000 medals in math?

@satellite73

anonymous · Answer

Triangle ABC is a 30˚ −60˚ −90˚ triangle with vertices A(2, 5) and B(2, −5). If m ∠B = 30˚ and ∠C is a right angle, what is the y-coordinate of C?

anonymous · Answer

@satellite73

anonymous · Answer

@imqwerty  @pooja195

aravindg · Answer

Circle is a geometrical figure we get by rotating a point with respect to a fixed point in equal distance. This distance is cled r and remains contant. Now the circumference is basically the perimeter of the fogure ie the length moved by it when it completes rotation. It is given by 2*pi*r.