Answer
8 mm
Work Step by Step
Figure 22–8 shows that satellite TV wavelengths are approximately 0.03 m (one significant figure).
In Example 22–2, a common type of antenna called a $\frac{1}{4}$-wave antenna is discussed, where the antenna has a length of $\frac{1}{4}$ the wavelength.
One-quarter of 0.03 m is 8 mm.