find the area sector of AOB

[tex]\textit{area of a sector of a circle}\\\\ A=\cfrac{\theta \pi r^2}{360}~~ \begin{cases} r=radius\\ \theta =\stackrel{degrees}{angle}\\[-0.5em] \hrulefill\\ r=12\\ \theta = 70 \end{cases}\implies \begin{array}{llll} A=\cfrac{(70)\pi (12)^2}{360}\implies A=28\pi \\\\\\ A\approx 87.96~cm^2 \end{array}[/tex]