Errata

Equation (3.7) Page 24

Equation (3.7) should be

$$
A(ABD)>A_\text{wedge}(ABD)>A(ABC)
$$

Equation (3.8) Page 24

Equation (3.8) should be

$$
\frac{1}{2}\tan \alpha > \frac{\alpha}{2} > \frac{1}{2}\sin \alpha
$$