so this is ratios actual height to shadow height=10 to 18=10:18=10/18=5/9 ratio is 5:9
if the shadow height=12 then find actual height x:12=5:9 since they should be in the same ratio x/12=5/9 multiply both sides by 12 x=60/9 x=6 and 6/9 x=6 and 2/3 height of person is 6 and 2/3 foot or 6.66ft or 6ft and 8 inches
