FeatureLesson Course 2 Lesson Main LESSON 8-6 Square Roots and Irrational Numbers Problem of the Day 8-6 Calculate the area of the figure below. Include units in your answer
FeatureLesson Course 2 Lesson Main LESSON 8-6 Square Roots and Irrational Numbers Problem of the Day 8-6 Area of Rectangle 1 = Base x Height = 4 x 10 = 40 Area of Rectangle 2 = Base x Height = 3 x (8 - 4) = 12 Find the area of the circle. Because it's a half-circle, we multiply the area by (1/2). Area of Circle = (1/2)(3.14)r 2 = (1/2)(3.14)1 2 = 1.57 Total Area = = cm 2 or square cm cm
FeatureLesson Course 2 Lesson Main LESSON 8-6 (For help, go to Lesson 2-1.) Simplify Square Roots and Irrational Numbers Check Skills You’ll Need 1. Vocabulary Review How do you find the square of a number? Check Skills You’ll Need 8-6
FeatureLesson Course 2 Lesson Main Solutions 1. Multiply the number by itself = 8 8 = = = = 2 2 = = 7 7 = 49 LESSON 8-6 Square Roots and Irrational Numbers Check Skills You’ll Need 8-6
FeatureLesson Course 2 Lesson Main Perfect square: a number that is a square of an integer (Integer: positive whole numbers, their opposites, and zero) 8 2 = 8 8 = 64; so 64 is a perfect square The inverse of squaring a number is finding a square root. 8 2 = 64
FeatureLesson Course 2 Lesson Main 81 = 9 81 = 9 2 LESSON 8-6 Simplify 81. Square Roots and Irrational Numbers Quick Check Additional Examples 8-6
FeatureLesson Course 2 Lesson Main 60 is between 7 and 8. Estimate the value of 60. LESSON 8-6 Find perfect squares close to < 60 < 64 Simplify. 7 < 60 < Since 60 is closer to 64 than it is to 49, Square Roots and Irrational Numbers Quick Check Additional Examples 8-6
FeatureLesson Course 2 Lesson Main Rational number: a number that can be written as a fraction (ratio of two integers) Irrational number: a number that cannot be written as a fraction. If it’s written as a decimal, it does not terminate nor does it repeat.
FeatureLesson Course 2 Lesson Main If a positive integer is not a perfect square, its square root is irrational. Rational Irrational
FeatureLesson Course 2 Lesson Main c. – b. 30 Identify each number as rational or irrational. a. 121 rational 121 is a perfect square. LESSON 8-6 irrational 30 is not a perfect square. rational It is a terminating decimal. d irrational The decimal neither terminates nor repeats. Square Roots and Irrational Numbers Quick Check Additional Examples 8-6
FeatureLesson Course 2 Lesson Main Estimate each square root Identify each as rational or irrational LESSON 8-6 about 2 rational about 5 irrational Square Roots and Irrational Numbers Lesson Quiz 8-6
FeatureLesson Course 2 Lesson Main Homework: Bring your 3-D object, ruler, scissors Lesson 8-6, pp , #s 1-38, all