## Precalculus: Concepts Through Functions, A Unit Circle Approach to Trigonometry (3rd Edition)

$25^o$C
Substitute the given value of the $F$ into the expression: $C=\dfrac {5}{9}\left( F-32\right) =\dfrac {5}{9}\left( 77-32\right) =\dfrac {5\times 45}{9}=25^o$