We are finding the perimeter of the stop sign, therefor we have to either multiply or add the value of 11. Since this sign is an octagon we will have to multiply by eight or add 11 eight times. This will give you an answer of 88 inches.
The amount of fish caught is at a constant decreasing rate of 17. 203-186=17, 186-169=17, 169-17=152. So all you have to do is subtract the constant rate from the last known number.