If 6-foot-tall madeleine casts an 108-inch shadow, how tall is her friend if, at the same time, his shadow is 1.5 feet shorter than hers? show work .

Step 1:
Write what you know

Madeline's Height: 6 ft
Madeline's Shadow: 108 in

Friend's Height: X (we use X as a variable because his height is unknown)
Friend's Shadow: 108 in - 1.5 ft
                              108 in - 18 in
                                 90 in

Step 2:
Set up proportions

6          x
=
108      90 

Step 3:
Cross Multiply & Solve

108x = 540
x = 5 ft tall