A’Leila is building a pen for her pet donkey. The pen is a rectangle with one side
measuring b yards and the adjacent side measuring a yards. A’Leila knows that
.
a. Write two different expressions giving the perimeter of the donkey’s pen.
b. Choose a value for a that is greater than 5 and less than 15. Evaluate the
perimeter of the pen for that value, using one of the expressions that you
wrote.
c. Explain why you used that expression to evaluate the perimeter of the
donkey’s pen
a. Two different expressions for the perimeter of the donkey's pen are:
Expression 1: P = 2a + 2b
Expression 2: P = 2(a + b)
b. Let's choose a value for a as 7. Using Expression 1, we can calculate the perimeter as follows:
P = 2a + 2b
P = 2(7) + 2b
P = 14 + 2b
To find the perimeter, we need to know the value of b. Let's say b is 9.
P = 14 + 2(9)
P = 14 + 18
P = 32
Therefore, when a = 7 and b = 9, the perimeter of the pen is 32 yards.
c. I chose Expression 1 (P = 2a + 2b) to evaluate the perimeter of the donkey's pen because it allows for the separate measurement of each side of the pen. Since we are given specific measurements for a and b, using this expression helps us calculate the total sum of all the sides accurately.