Answer: P is arc; Q is the centre of the circle; R is the radius; S is the circumference
Step-by-step explanation: P is arc: it is a continuous part of the circumference (S) of the circle;
Q is the centre of the circle which is at any point in time R points away from P;
R is the radius: the line segment between any point of a circle and its centre, Q;
S is the circumference of the circle: the line that bounds a circle.