Respuesta :

for #1
you would do 
8 + 8 + 5 + 5 = 26
so they use 26 inches of ribbon

for #2 
since there is 8 sides and each side is 3 feet we multiply 
8 x 3 = 24 
so the perimeter of her collage room is 24 feet

for #3
its cut off...