Show me the picture of the octagon. But remember that if the diameter is shown than always do half of the diameter to get the radius. Hope this helps
Answer:
Option A.

Step-by-step explanation:
see the attached figure with letters to better understand the problem
In this problem we have a triangle with a circle inscribed in it
so

step 1
Find the length side B.C

substitute the given values

step 2
Find the length side C.D
Remember that

therefore

step 3
Find the length side E.D
we know that

substitute the given values

step 4
Find the length side E.F
Remember that

therefore

step 5
Find the length side A.F
Remember that

therefore

step 6
Find the perimeter


To solve this
problem, let us analyze this step by step. The temperature for each day is as
follows:
Water temperature
on Sunday = 78 degrees F
Water temperature
on Monday = changed by -3 degrees F
Water temperature
on Tuesday = changed by 3 degrees F
We can see that
the total change of water temperature from Sunday to Tuesday is:
-3 + 3 = 0
Therefore there
is zero overall change. There the integer which represents the temperature
change is “0”.
Since the overall
change in water temperature is zero, hence the temperature on Sunday and on
Tuesday is similar.
Water temperature
on Tuesday = 78 degrees F