Chapter 1, Problem 14P

A rectangular box has the dimensions shown.

(a) Determine the angle BAC to the nearest degree.

(b) Determine the area of the triangle ABC to the nearest tenth of a centimeter.

Law of cosines: $c^2{\text{a}}^{\text{2}}+{\text{b}}^{\text{2}}-\text{2abcos}\gamma$

Herons formula for triangular area: $A=\sqrt{p(p-a)(p-b)(p-c)}$, where $p=\left(a+b+c\right)/2$.