Let's go through each question and determine the correct answers.

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1. The side length of a square is equal to?

For a square, if the area is $A$ and the side length is $s$, then the area $A$ is given by $A = s^2$. Solving for $s$, we find $s = \sqrt{A}$.

Correct answer: B. the square root of its area

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2. Which of the following statements is true?

• A. The square root of an integer will not always be an integer (e.g., $\sqrt{2}$ is not an integer).
• B. The square of an integer will always be an integer (e.g., $2^2 = 4$, which is an integer).

Correct answer: B. The square of an integer will always be an integer

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3. Which of the following numbers has a square root of 9?

The number whose square root is 9 must be $9^2 = 81$.

Correct answer: D. 81

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4. Which of the following numbers is a perfect square?

A perfect square is an integer that can be expressed as the square of another integer:

• 16 is $4^2$, so it is a perfect square.

Correct answer: C. 16

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5. Which of the following statements is true about the square root of 139?

To estimate, note that:

• $11^2 = 121$ and $12^2 = 144$.
• Thus, $\sqrt{139}$ lies between 11 and 12.

Correct answer: D. The square root of 139 has a value between 11 and 12

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Would you like further explanations on any of these answers, or do you have any questions?

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Related Questions

1. What is the formula to calculate the area of a square given its side length?
2. Can a negative integer have an integer square root?
3. Why is the square of any real number always non-negative?
4. How can you identify a perfect square quickly?
5. How can we approximate square roots for non-perfect squares like 139?

Tip: When estimating square roots, remember the squares of numbers around the target for a quick estimate of the range.