You have two good answers above (2 and a half), but I decided to give you one more, to add some useful details.
Celsius is based on the freezing and boiling points of water. 0˚ celsius is the temperature water freezes, and 100˚ celsius is the temperature at which it boils (at standard pressure).
If you are used to the Fahrenheit scale, then you should know these values are 32˚ and 212˚ respectively.
So 0˚ C = 32˚ F, and 100˚ C = 212˚ F.
Armed with these two data points, you can derive the conversion equations. Remembering that the conversion factor is 9/5 (or 5/9) makes the task even easier--you don't have to find the slope.
Clearly the difference between degrees C is greater than the diffence between degrees F. (100-0 < 212-32). So we must multiply C by a number larger than 1 (9/5) to convert to F.
9/5C + 32 = F when C=0. (You can do this in your head)
9/5C + 32 = F when C=100 (Check with pencil & paper)
You can algebraically manipulate the above to derive the conversion for Fahrenheit:
9/5C = F - 32 [subtract 32 from each side]
C = 5/9(F - 32) [Multiply both sides by 5/9]
Where did the 5/9 or 9/5 (line slope) come from?
In algebra, y = mx + b is the slope-intercept form of an equation. If we set Fahrenheit=y and Celsius=x,
F = mC + b. Using our data points:
32 = m(0) + b
212 = m(100) + b
Now we have two equations and two unknowns.
It is trivially easy from the first equation that b=32.
66 degrees Fahrenheit = 18.8888889 degrees Celsius A very good , easy and fast way for conversion online is google. In the google Search box just type "66 degrees fahrenheit in celsius" and click on search and it will give u the results! It can be also used for either kind of conversions like miles to km, km to miles, inches to cm , pounds to kg etc. etc.
Comments
You have two good answers above (2 and a half), but I decided to give you one more, to add some useful details.
Celsius is based on the freezing and boiling points of water. 0˚ celsius is the temperature water freezes, and 100˚ celsius is the temperature at which it boils (at standard pressure).
If you are used to the Fahrenheit scale, then you should know these values are 32˚ and 212˚ respectively.
So 0˚ C = 32˚ F, and 100˚ C = 212˚ F.
Armed with these two data points, you can derive the conversion equations. Remembering that the conversion factor is 9/5 (or 5/9) makes the task even easier--you don't have to find the slope.
Clearly the difference between degrees C is greater than the diffence between degrees F. (100-0 < 212-32). So we must multiply C by a number larger than 1 (9/5) to convert to F.
9/5C + 32 = F when C=0. (You can do this in your head)
9/5C + 32 = F when C=100 (Check with pencil & paper)
You can algebraically manipulate the above to derive the conversion for Fahrenheit:
9/5C = F - 32 [subtract 32 from each side]
C = 5/9(F - 32) [Multiply both sides by 5/9]
Where did the 5/9 or 9/5 (line slope) come from?
In algebra, y = mx + b is the slope-intercept form of an equation. If we set Fahrenheit=y and Celsius=x,
F = mC + b. Using our data points:
32 = m(0) + b
212 = m(100) + b
Now we have two equations and two unknowns.
It is trivially easy from the first equation that b=32.
From the second, m=(212-32)/100 = 180/100 = 9/5
Take the degrees Fahrenheit, subtract 32 degrees, and divide by 1.8.
From Celsius to Fahrenheit, multiply by 1.8 then add 32 degrees.
60 C X1.8 = 108
108 + 32 = 140 degrees F
66 degrees Fahrenheit = 18.8888889 degrees Celsius A very good , easy and fast way for conversion online is google. In the google Search box just type "66 degrees fahrenheit in celsius" and click on search and it will give u the results! It can be also used for either kind of conversions like miles to km, km to miles, inches to cm , pounds to kg etc. etc.
Fahrenheit to Celsius °C = (°F − 32) ÷ 1.8
Celsius to Fahrenheit °F = (°C × 1.8) + 32
F = 9/5C +32
(F-32)5/9 = C
(60-32)5/9 = C
28*5/9 = C
To see the formula go to this link
http://www.srh.noaa.gov/elp/wxcalc/formulas/tempCo...
or just use the weather calculator
http://www.srh.noaa.gov/elp/wxcalc/wxcalc.shtml