Main Idea and New Vocabulary

Example 1: Find Squares of Numbers

Example 2: Find Squares of Numbers

Key Concept: Square Root

Example 3: Find Square Roots

Example 4: Find Square Roots

Example 5: Real-World Example

• Find squares of numbers and square roots of perfect squares.

• square

• perfect squares

• square root

• radical sign

Find Squares of Numbers

Find the square of 5.

5 ● 5 = 25 Multiply 5 by itself.

Answer: The square of 5 is 25.

A. 5.2

B. 22

C. 110

D. 121

Find the square of 11.

Find the square of 19.

Find Squares of Numbers

Method 1 Use paper and pencil.

19× 19

171+ 190 361

Multiply 19 by itself.

Annex a zero.

Method 2 Use a calculator.

19 361ENTERx2

Answer: The square of 19 is 361.

A. 40

B. 200

C. 400

D. 440

Find the square of 20.

Find Square Roots

Find

6 ● 6 = 36, so What number times itself is 36?

Answer:

A. 2

B. 4

C. 8

D. 16

Find

Find Square Roots

Answer: So,

Find

676 26ENTER2nd

A. 17

B. 23

C. 27

D. 33

Find

GARDENS A city planner is designing a new community garden. The garden will be in the shape of a square and have an area of 1,225 square feet. What are the dimensions of the garden?

The garden is a square. By finding the square root of the area, 1,225, you find the length of one side of the garden.

Answer: The dimensions of the garden are 35 feet by 35 feet.

33 ● 35 = 1,225, so

A. 2.25 ft by 2.25 ft

B. 15 ft by 15 ft

C. 25 ft by 25 ft

D. 112.5 ft by 112.5 ft

PATIOS Philip is building a patio in the back yard. The patio will be square and will have an area of 225 square feet. What are the dimensions of the patio?