To convert from Fahrenheit to Celsius, you can use the formula:
\[ C = \frac{(F - 32) \times 5}{9} \]
Plugging in 84 degrees Fahrenheit:
\[ C = \frac{(84 - 32) \times 5}{9} \]
\[ C = \frac{52 \times 5}{9} \]
\[ C = \frac{260}{9} \approx 28.89 \]
Rounding to two significant digits, the temperature in Celsius is approximately:
\[ 29 , \text{°C} \]