By analyzing the diagram, identifying key relationships, and applying the Pythagorean theorem, we found that the radius of circle R is 3 units.
The correct answer is option a "3".
1. Analyze the diagram:
The diagram shows circle R with several chords and segments:
TH: A chord of the circle with length 3.
HW: A diameter of the circle with length 9.
SH: A segment connecting the midpoint of TH to a point on the circle.
2. Key relationships:
A diameter bisects a chord. Therefore, HS = HT = TH / 2 = 3 / 2.
A radius drawn to the midpoint of a chord is perpendicular to the chord.
3. Applying the Pythagorean theorem:
In right triangle SHS, where SH is half the chord length (3/2) and HS is the radius (unknown), we can use the Pythagorean theorem:

Substituting the known values:

Solving for HS (radius):



HS = √9 = 3
Therefore, the radius of circle R is 3 units.
Answer: (a) 3