This is a test of commonsense. Complete the next sentence:

How to make blinds 
Measure the window. 
Use a tape measure to determine the width and length of the window you want covered. 
Determine the length of the fabric and lining.
Add 2 inches (5 cm) of seam allowance to the length measurement. For a 72-inch (1.8-m) long window, the fabric and lining should each be 74 inches (1.88 m) long.