Question 4a: To calculate the perimeter of a rectangle, A'Leila can use the formula for the perimeter \( P \):
- \( P = a + a + b + b \) (which simplifies to \( 2a + 2b \))
- \( P = 2a + 2b \)
- \( P = a + 2b + a \) (which also simplifies to \( 2a + 2b \))
- \( P = 2b + a + a \) (which also simplifies to \( 2a + 2b \))
So the valid formulas to calculate the perimeter are:
- \( a + a + b + b \)
- \( 2a + 2b \)
- \( a + 2b + a \)
- \( 2b + a + a \)
The invalid formulas are:
- \( a \times b \) (which calculates the area, not the perimeter)
- \( a + 2b \) (this does not give the full perimeter)
- \( a + 2b \) again (same reason)
Question 4b: Given that \( a = 12b \) and that side \( b \) is going to be 12 meters:
\( a = 12 \times 12 = 144 \) meters
So, side \( a \) should be 144 meters.
However, if we are only considering \( b \) as 12 (thus using \( a = (12)b \) will not yield any viable options), the provided options seem incorrect. Based solely on the function \( a = 12b \) it is not possible to choose one of them given that none specify \( 144 \) meters.
Question 4c: To calculate the perimeter using the dimensions from part b:
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Since \( a = 144 \) meters and \( b = 12 \) meters, we can use the perimeter formula:
\( P = 2a + 2b = 2(144) + 2(12) = 288 + 24 = 312 \) meters
However, since this value is not one of the multiple choices given in part c (72, 49, 48, 36), there seems to be an inconsistency.
To recap,
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Valid perimeter formulas for 4a are:
- \( 2a + 2b \) or \( a + a + b + b \)
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For 4b, if strictly adhering to \( a = 12b \), and \( b = 12 \) meters, results in \( 144 \) meters which was not supplied above.
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Finally, using \( b = 12 \) and the calculated \( a \) results would lead to a perimeter choice of 312 meters, once again falling outside the original options.
This indicates a discrepancy in the question formatting/choices providing no matching perimeter measurements based on derived calculations.