Question: Which circle has a radius that measures $10$ units? top-left: circle with a slanted segment labeled $10$, center marked $D$; the segment appears to be a diameter, not a radius. top-left: circle with a slanted segment labeled $20$, center marked $F$; the segment appears to be a diameter. center: circle with a slanted segment labeled $10$, center marked $G$; the segment passes through the center and appears to be a diameter. bottom-left: circle with a slanted segment labeled $20$, center marked $H$; the segment appears to be a chord.

1. **Problem Statement:** Identify which circle has a radius measuring $10$ units. 2. **Key Concept:** The radius of a circle is the distance from the center to any point on the circle. 3. **Given Information:** - Top-left circle with center $D$ has a segment labeled $10$ units, but it is a diameter (passes through the center and touches two points on the circle). - Another top-left circle with center $F$ has a segment labeled $20$ units, also a diameter. - Center circle with center $G$ has a segment labeled $10$ units, which is a diameter. - Bottom-left circle with center $H$ has a segment labeled $20$ units, which is a chord (does not pass through the center). 4. **Analysis:** - Diameter $= 2 \times$ radius. - For the circles with diameter $10$, radius $= \frac{10}{2} = 5$ units. - For the circle with diameter $20$, radius $= \frac{20}{2} = 10$ units. - The chord length does not represent radius. 5. **Conclusion:** - The circle with center $F$ has a diameter of $20$ units, so its radius is $10$ units. **Final answer:** The circle with center $F$ has a radius measuring $10$ units.