Chapter 1 - Section 1.2 - Exponents and Radicals - 1.2 Exercises - Page 24: 102

$D \approx 41.26$

We have $$ D = \sqrt{2rh + h^{2}} \\ r = 3960 \space mi \\ h = 1135 \space ft \approx 0.215\text{ miles} $$ Then, we could write $D = \sqrt{2 \times 3960 \times 0.215 + 0.215^2}$ $D \approx \sqrt{1702.85}$ So we have $D \approx 41.26$