Note that an \(\displaystyle{8}{\left(\frac{{1}}{{2}}\right)}×{11}\) sheet of paper is measured in inches.

The area of a triangle with base b and corresponding height h is given by: \(\displaystyle{A}={\left(\frac{{1}}{{2}}\right)}{b}{h}\)

Substitute \(b=8.5\) in. and \(h=11\) in.: \(\displaystyle{A}={\left(\frac{{1}}{{2}}\right)}{\left({8.5}\right)}{\left({11}\right)}\)

\(\displaystyle{A}={46.75}\in^{{2}}\)