[tex]\bf (\stackrel{\stackrel{x}{adjacent}}{7}~~,~~\stackrel{\stackrel{y}{opposite}}{6})\impliedby \textit{let's find the \underline{hypotenuse}}
\\\\\\
\textit{using the pythagorean theorem}\\\\
c^2=a^2+b^2\implies c=\sqrt{a^2+b^2}\qquad
\begin{cases}
c=hypotenuse\\
a=adjacent\\
b=opposite\\
\end{cases}
\\\\\\
c=\sqrt{7^2+6^2}\implies c=\sqrt{85}\\\\
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sec(\theta)=\cfrac{hypotenuse}{adjacent}\qquad \qquad sec(\theta)=\cfrac{\sqrt{85}}{7}[/tex]