Question

The center of circle Q has coordinates (3, -2). If circle Q passes through R(7, 1), what is the length of its diameter?

A. 50
B. 25
C. 10
D. 5

Answer 1

The radius is |QR| = √((7-3)² +(1-(-2))²) = √(16+9) = 5.

The diameter is twice the length of the radius: 2×5 = 10.

The appropriate choice is ...
 C. 10