## Elementary Geometry for College Students (5th Edition)

$\approx$ 106°
$\frac{longer diagonal}{2}$= $\frac{shorter diagonal}{2}$ $\times$ tan $\frac{obtuse angle}{2}$ 8 in. = 6 in. $\times$ tan $\frac{obtuse angle}{2}$ tan $\frac{obtuse angle}{2}$ = $\frac{4}{3}$ $\frac{obtuse angle}{2}$ $\approx$ 53° obtuse angle $\approx$ 106°