Square Roots of Perfect Squares Math 9 Lesson 1.1 Square Roots of Perfect Squares

Focus: Determine square roots of decimals and fractions that are perfect squares. Introduction: (page 6) Playground is 400 m2 Find the side length of the playground Find the amount of fencing required for all sides

Notes: To find the area of a squre, square it’s side length (2 cm)2 = 4 cm2 2 cm The area is 4 cm2 A = s2 15 10 = ( 15 10 )2 = 225 100 units2

To calculate the side length of a square given the area  find the square root of the area If the area of a square is 169 100 then the side length is 169 100 = 13 10  1 3 10

** Squares and square roots are opposite operations ** Fractions that are perfect squares are: fractions that in simplest form are perfect squares if it can be written as the product of 2 equal fractions Ex: 1 4 is ( 1 2 ) ( 1 2 )

Are the following perfect squares? 16 25 8 18 11 16

Decimals that are perfect squares Rewrite the decimal as a fraction in lowest terms – then treat it as a fraction Ex: 0.25 = 25 100 = 1 4 = 1 2 x 1 2 Try: 1.69 2.5

Summary Which of the following are perfect squares? 181 225 349 91 6 22 49 121 49 0.0289 1.69

Homework Pages 11-31 # 1, 2, 5a-f, 8, 9ace, 11ab, 13a, 14 and 15 If you are on a different program do: #4, 6, 7abcd, 10(use a calculator) and 14