Method of measurement
In order to calculate the required length of the architrave on the window cut 45 degree angle:First thing you need to do is multiply the inside of the window reveal (h) by 2 and add the width (a), then multiply the width (b) by 4. (2 x h + a) + 4 x b 

In order to calculate the required length of the architrave on the window together with beads:You need to multiply the inside of the window reveal (h) by 2 and add the width of the window (a). 2 x h + a 

In order to calculate the required length of cornice above the window:You need to multiply the width of the architrave (b) by 2 and add the width of the inside of the window reveal (a), than multiply by 4 the depth of the cornice (c) and the result, add to your previously done measurements. (2 x b + a ) + 4 x c 

In order to calculate the required length of cornice under the sill window:You need to multiply by 2 the width of the architrave (b) and add width of the inside of the window reveal (a), then multiply the depth of the cornice (c) by 4 and the result,add to your previously done measurements. (2 x b + a ) + 4 x c 

