For 15 the answer is 8
for 16 the answer is 9
for 17 the answer is 1
Answer: 5 feet.
Step-by-step explanation:
Remember that the lenghts of the sides of a regular octagon are equal.
You can observe in the figure that the lenght of a side of the regular octagon is 1.25 inches.
Let be "s" the actual length of a side of the regular octagon.
Knowing that the scale drawing has a scale of 1 inch 4 feet, you can find the actual lenght of a side of this regular octagon with:

Therefore, the actual length of a side of the octagon is 5 feet.
The discount is $2. 2/20 is 0.1 or 1/10 which as a percentage would be 10%. The discount of $2 is <u><em>10%</em></u> off.