So perimeter is adding all sides
In this picture, you have all sides, so add them up!
(2a-3)+(3a+1)+(2a) = P
So this expression shows that we're adding all sides that gives us the P, or perimeter :)
For #11 you add 54 + 59+ 57+ 54. Then you have 224. Then divide 224 by 4 since there are 4 numbers. Your answer should be 56 inches as the average, or mean.
Remember, when you divide, you divide by the number of all the numbers. I'm trying to make sense but hope this helps!
Answer:
Step-by-step explanation:
If you divide 
by 4 (both numerator and denominator)
You get which is equivalent to the given ration
As it appears to be the same thing on both sides so far wouldn't you think that it's 8?
No because there are 20 multiplied by 3 is 60. So the answer would be 60+144=204x12=2448 but the last answer was still correct
