2. Lesson Menu Main Idea and New Vocabulary Key Concept:Square Root Example 1:Find Square Roots Example 2:Find Square Roots Example 3:Find Square Roots Example 4:Find Square Roots Example 5:Use Square Roots to Solve an Equation Example 6:Real-World Example

3. Main Idea/Vocabulary Find square roots of perfect squares. perfect square square root radical sign

4. Key Concept

5. Example 1 Find Square Roots Find. Answer:9 Find the positive square root of 81; 9 2 = 81.

6. Example 1 CYP A.5 B.10 C.–10 or 10 D.no real square root Find.

7. Example 2 Find Square Roots Find. Find both square roots of 1.44; 1.2 2 = 1.44. Answer:  1.2

8. Example 2 CYP A.  6 B.0.6 C.  0.6 D.  0.06 Find.

9. Example 3 Find Square Roots Find. Answer: Find the negative square root of

10. Example 3 CYP Find. A. B. C. D.no real square root

11. Example 4 Find Square Roots Find. Answer: There is no real square root because no number times itself is equal to –49.

12. Example 4 CYP A.–11 B.11 or –11 C.–1.1 D.no real square root Find.

13. Example 5 Use Square Roots to Solve an Equation ALGEBRA Solve x 2 = 225. x 2 = 225 Write the equation. x= Definition of square root Answer: The equation has two solutions, 15 and –15. x = 15 and –15 Check 15 15 = 225 and (–15)(–15) = 225

14. Example 5 CYP A.20 B.20 and –20 C.40 and –40 D.no real square root ALGEBRA Solve n 2 = 400.

15. Example 6 PUZZLE A square puzzle has an area of 35,721 square millimeters. What is the length of a side of the square?

16. Example 6 s 2 = 35,721 Write the equation. 35,721= 3 3 3 3 3 3 7 7 Find the prime factors. = (3 3 3 7)(3 3 3 7) Regroup into two equal factors. Definition of square root To find, find two equal factors of 35,721.

17. Example 6 Answer: Since distance cannot be negative, the length of each side is 189 millimeters. So, s = 3 3 3 7 or 189.

18. Example 6 CYP A.57 ft B.114 ft C.228 ft D.6,498 ft MAZES A square corn maze has an area of 12,996 square feet. What is the length of a side of the square?