Question 4
4a. Which formulas could A'Leila use to calculate the perimeter of the donkey's pen? Be sure to select ALL that would work to calculate the perimeter. (2 points)
The formulas for calculating the perimeter \( P \) of a rectangle with dimensions \( a \) and \( b \) are:
- \( a + a + b + b \) (This simplifies to \( 2a + 2b \))
- \( 2a + 2b \) (This is the standard formula for the perimeter)
- \( a \times b \) (This is incorrect; it calculates the area, not the perimeter)
- \( a + 2b \) (This is incorrect; it does not give the full perimeter of the rectangle)
Correct Responses:
- \( a + a + b + b \)
- \( 2a + 2b \)
4b. A'Leila knows that \( a = \frac{1}{2} b \). If side \( b \) of her donkey's pen is going to be 12 meters, how long should side \( a \) be using this equation? (1 point)
Since \( b = 12 \):
\[ a = \frac{1}{2} b = \frac{1}{2} \times 12 = 6 \text{ meters} \]
Correct Response:
- 6 meters
4c. Using the dimensions from part b of this question, calculate the perimeter of the donkey's pen. (2 points)
Using \( a = 6 \) meters and \( b = 12 \) meters, we can calculate the perimeter:
\[ P = 2a + 2b = 2 \times 6 + 2 \times 12 = 12 + 24 = 36 \text{ meters} \]
Correct Response:
- 36 meters