Discover Martha's Magic Day: Longest Hair Contest Follow these step-by-step instructions to calculate the ratio of your hair length to your height to enter the contest by Monday, June 18.From a level ruler on the top of your head: OK * 1. Measure your height. My Height (H) in centimeters is: OK * 2. Measure the length of your hair.The Length (L) of my hair in centimeters is: OK * 3. Calculate the ratio, L/H, and express as a decimal (For example: 30/128 = 0.2344)The ratio of the length of my hair to my height is: OK OK NEXT