How do i work out the nouns of a pitched roof? some quick division would be best-thanks in credit!

some quick division would be best-thanks in credit!
Different types of gas *Furnaces* Question?
Answers:    hope this will help...

http://pdf.hunterplastics.co.uk/pdf/rain...

http://www.roofingchildsplay.com/article...
Do you still hold to sweep your chimney...
Length x rise still works. Or do mean the inside volumn nouns? If this is the case, we call for more info.