The waist to hip ratio is the ratio, commonly expressed as a decimal that has been shown to be a good predictor of possible cardiovascular problems in both men and women. if a man has a wh are greater than one, he is considered to be at high risk for cardiovascular problems. calculate the whr of the male with a waist measurement of 40 inches and a hip measurement of 2 inches less.

(both women and men)=2
greater than one with that substitute in this example we will us 12 bigger then 1   2+12+1=15
WHR waist measurement would be out of 40 inches it would be 20 divide by 40= 0.5 so count that to a 5 limit 
hip measurement 2 less so then you would say 20 divide by 40 minus 2= -1.5 which equals as i typed - 1.5 so - 1.5 is your in step what you do is 
step.1- find out what 2+12+1=
step.2- find the WHR waist measurement 
step.3- then divide your waist measurements
step.4 - find the hip measurement that's less then 2 and divide it to get the answer to the proublem :P
Hope i could help :)

If the diameter is 8 than the radius is 4 because 2r or 2*radius equals the diameter. 4*2=8. 8/2=4.