Answer:
the diameter is twice the circle radius, or 20
Explanation:
Recall that the radius is half the diameter <=> the diameter is twice the radius. In this problem we need to find the radius first, then multiply it by 2 to obtain the diameter.
We need to determine the distance between the center of the circle Q(6, -4) and the point R(14, 2) on the circle.
The Pythagorean Theorem applies here. Going from Q to R, x changes from 6 to 14, or 8 units, which is the horizontal leg of a right triangle, and y changes from -4 to 2, or 6 units. Thus, according to the Pythagorean Theorem, the length of the hypotenuse of this triangle is
r = √(6² + 8²) = √100 = 10
and so the diameter is twice that, or 20.