Question

three uses 8 pieces of glass per square foot to make a stained glass window how many pieces of glass will he need to make a window that is 864 square inches

Answer 1

1 foot = 12 inches
864/12=72 The window is 72 square feet.
A man uses 8 pieces of glass per square foot to make a stained glass window. So he needs to use 72*8=576 pieces of glass.