I am assuming that you are decorating only one colum (pole)
If this is the case, we need to find out how many inches of ribbon you need to wrap around the colum (pole), and then add the length of the ribbon needed to make the bow. We are told that for bow we need 18 inches of ribbon.
Now, we needed to find the distance around the colum (pole). When we talk about the distance around an object that is round, such as this column (pole), we need to find the circumference of the colum (pole). You might recall that there are two formulas to find the circumference:
1). C = 2 (Pi) (radius)
2). C= (diameter) (pi)
Since the problem gives us the diameter, let's us the second formula. Also, you need to know thar 1 foot 6 inches is equal to 1.5 ft. ( Remember: 12 inches is equal to one foot). So, the diameter is 1.5. In addition, I am going to use 3.214 for Pi. Let's proceed and plug in the values into the second formula
c = (diameter) (Pi)
(1.5) (3.14) multiplying we get
c= 4.71. This represent the length of the ribbon that you are going to use to wrap around the colum (pole). To this, you need to add the length of the bow to find the total length. This is what we have:
4.71+ 18 = 22.71 inches. This represents the length of the ribbon that you are going to need.
I hope this helps you out.
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