Refer to our Texas Go Math Grade 4 Answer Key Pdf to score good marks in the exams. Test yourself by practicing the problems from Texas Go Math Grade 4 Lesson 12.3 Answer Key Model Perimeter Formulas.

## Texas Go Math Grade 4 Lesson 12.3 Answer Key Model Perimeter Formulas

**Essential Question**

How can you use a formula to find the perimeter of a rectangle?

Answer:

Perimeter of rectangle = (2 × length) + (2 × width)

Rectangle consists of four sides and the sum of all length of sides is the perimeter of rectangle.

Explanation:

Perimeter of a Rectangle = length + width + length + width

**Unlock the Problem**

Julio is putting a stone border around his rectangular garden. The length of the garden is 7 feet. The width of the garden is 5 feet. How many feet of stone border does Julio need?

- Circle the numbers you will use.
- What are you asked to find?

Answer:

24 feet

Explanation:

The length of the garden is 7 feet. The width of the garden is 5 feet

7 + 5 + 7 + 5 = 24

The perimeter is 24 feet.

So, Julio needs 24 feet of stone border.

Perimeter is the distance around a figure.

To find how many feet of stone border Julio needs, find the perimeter of the garden.

**Use addition.**

Perimeter of a Rectangle = length + width + length + width

7 + 5 + 7 + 5 = __________

The perimeter is __________ feet.

So, Julio needs __________ feet of stone border.

Answer: 24 feet

Explanation:

Perimeter of a Rectangle = length + width + length + width

7 + 5 + 7 + 5 = 24

The perimeter is 24 feet.

So, Julio needs 24 feet of stone border.

**Use Multiplication**

(A) Find Perimeter of a rectangle

Perimeter = (2 × length) + (2 × width), or 2l + 2w

Perimeter = (2 × 12) + (2 × 8)

= 24 + 16

= ____________

So, the perimeter is __________ centimeters.

Answer: 40 cm

Explanation:

length = 12 cm

width = 8 cm

Perimeter = (2 × 12) + (2 × 8)

= 24 + 16 = 40 centimeter

So, the perimeter is 40 centimeters.

(B) Find Perimeter of a Square

Perimeter = 4 × one side, or 4 × s

Perimeter = 4 × 16

= ___________

So, the perimeter is ___________ inches.

Answer: 64 inches

Explanation:

Perimeter = 4 × 16 = 64 inches

So, the perimeter is 64 inches.

Use a Formula A formula ¡s a mathematical rule. You can use a formula to find perimeter.

**Example** Find the perimeter of the rectangle.

P = (2 × l) + (2 × w)

= (2 × ______ ) + (2 × __________ ) Think: Write the measures you know.

= __________ + ___________ Think: Do what is in parentheses first.

= ___________

The perimeter of the rectangle is ______________ .

Answer:

P = (2 × l) + (2 × w)

= (2 × 18) + (2 × 14) Think: Write the measures you know.

= 36 + 28 Think: Do what is in parentheses first.

= 64 m

The perimeter of the rectangle is 64 m.

Explanation:

A rectangle is a parallelogram all of whose angles are right angles; especially one with adjacent sides of unequal length.

It has 4 sides and 4 vertices

Perimeter of rectangle = (2 × length) + (2 × width)

**Share and Show**

Question 1.

Find the perimeter of the rectangle.

P = (___________ × ___________) + (___________ × ___________)

= (___________ × ___________) + (___________ × ___________)

= ___________ + ___________

= ___________

The perimeter is ___________ feet.

Answer:

P = (2 × l) + (2 × w)

P = (2 x 8) + (2 x 4)

= 16 + 8 = 24 ft

Explanation:

A rectangle is a parallelogram all of whose angles are right angles; especially one with adjacent sides of unequal length.

It has 4 sides and 4 vertices.

Perimeter of rectangle = (2 × length) + (2 × width)

**Find the perimeter of the rectangle or square.**

Question 2.

___________ yards

Answer:

40 yards

Explanation:

Perimeter of rectangle (p) = (2 × length) + (2 × width)

P = (2 × l) + (2 × w)

P = (2 x 16) + (2 x 4)

P = 40 yards

Question 3.

_____________ meters

Answer: 304 m

Explanation:

Perimeter of rectangle (p) = (2 × length) + (2 × width)

P = (2 × l) + (2 × w)

P = (2 x 42) + (2 x 110)

= 84 + 220

= 304 m

Question 4.

_____________ meters

Answer: 16m

Explanation:

Perimeter of square = 4 x side

P = 4 x 4 = 16 m

**Math Talk**

Mathematical Processes

Can you use the formula P = (2 × l) + (2 × w) to find the perimeter of a square? Explain.

Answer: Yes

Explanation:

Perimeter ‘P’

Perimeter of rectangle is P

Perimeter of a Rectangle = length + width + length + width

P = (2 × length) + (2 × width)

**Unlock the Problem**

Question 5.

**H.O.T. Multi-step** Alejandra plans to sew fringe on a scarf. The scarf is shaped like a rectangle. The length of the scarf is 48 inches. The width is one half the length. How much fringe does Alejandra need?

(A) 72 inches

(B) 96 inches

(C) 120 inches

(D) 144 inches

Answer:

Option(D)

Perimeter of a Rectangle = length + width + length + width

P = (2 × length) + (2 × width)

= (2 x 48) + (2 x 24)

= 96 + 48 = 144 inches

a. Draw a picture of the scarf, and label the given measurements on your drawing.

Answer:

b. What do you need to find?

Answer:

The perimeter of the scarf

c. What formula will you use?

Answer:

Perimeter of rectangle.

P = (2 × length) + (2 × width)

d. Show the steps you use to solve the problem.

Answer:

Perimeter of a Rectangle = length + width + length + width

P = (2 × length) + (2 × width)

= (2 x 48) + (2 x 24)

= 96 + 48

= 144 inches

e. Complete.

‘The length of the scarf is __________ inches.

The width is one half the length or __________ ÷ 2.

The width is __________ inches.

So, the perimeter is (__________ × __________) + ( __________ × __________) = __________ inches.

Fill in the bubble for the correct answer choice above.

Answer:

‘The length of the scarf is 48 inches.

The width is one half the length or 48 ÷ 2.

The width is 24 inches.

So, the perimeter is ( 2 × 48) + (2 ×24) = 144 inches.

Question 6.

**H.O.T. Reasoning** What is the side length of a square with a perimeter of 44 centimeters?

(A) 4 centimeters

(B) 11 centimeters

(C) 22 centimeters

(D) 176 centimeters

Answer:

Option(D)

Explanation

P = 4 x side

= 4 x 44

= 176 centimeters

Question 7.

**Apply** Mr. Wong is putting a brick edge around his rectangular patio. What is the perimeter of the patio?

(A) 28 ft

(B) 38 ft

(C) 56 ft

(D) 66 ft

Answer:

Option(C)

Explanation:

Perimeter of a Rectangle = length + width + length + width

P = (2 × length) + (2 × width)

= (2 x 18) + (2 x 10)

= 36 + 20

= 56 ft

**Daily Assessment Task**

**Fill in the bubble completely to show your answer.**

Question 8.

A rectangular swimming pool is 24 feet long and 12 feet wide. What is the perimeter of the swimming pool?

(A) 288ft

(B) 36ft

(C) 60ft

(D) 72ft

Answer:

Option(D)

Explanation:

Perimeter of a Rectangle = length + width + length + width

P = (2 × length) + (2 × width)

= (2 x 24) + (2 x 12)

= 48 + 24

= 72 ft

Question 9.

Todd is putting a fence around a square shaped section of his backyard. The square section is 102 m on each side. How many meters of fence does Todd need in all?

(A) 408 m

(B) 104 m

(C) 800 m

(D) 204 m

Answer:

Option(A)

Explanation:

Perimeter of a Rectangle = length + width + length + width

P = 4 × side

= (4 x 102)

= 408 m

Question 10.

**Multi-Step** Joe is putting payers around his rectangular patio. The width of the patio is 14 feet. The length is three times the width. flow many feet of payers does he need?

(A) 34 ft

(B) 588 ft

(C) 112 ft

(D) 168 ft

Answer:

Option (C)

Explanation:

Perimeter of a Rectangle = length + width + length + width

P = (2 × length) + (2 × width)

= (2 x 14) + (2 x 3×14)

= 28 + 84 = 112

**TEXAS Test Prep**

Question 11.

Lola is putting a border on the quilt she is making. The quilt is shaped like a rectangle. The width of the quilt is 48 inches and its length is twice its width. How much border does Lola need?

(A) 96 inches

(B) 288 inches

(C) 144 inches

(D) 192 inches

Answer:

Option(B)

Explanation:

Perimeter of a Rectangle = length + width + length + width

P = (2 × length) + (2 × width)

= (2 x 48) + (2 x 2 x 48)

= 96 + 192 = 288 inches

### Texas Go Math Grade 4 Lesson 12.3 Homework and Practice Answer Key

**Find the perimeter of the rectangle or square.**

Question 1.

____________ feet

Answer: 28 feet

Explanation:

Perimeter of a Rectangle = length + width + length + width

P = (2 × length) + (2 × width)

= (2 x 6) + (2 x 8)

= 12 + 16 = 28 ft

Question 2.

____________ yards

Answer:

24 yards

Explanation:

P = 4 x side

= 4 x 6 = 24 yd

Question 3.

____________ meters

Answer:

18 meters

Explanation:

Perimeter of a Rectangle = length + width + length + width

P = (2 × length) + (2 × width)

= (2 x 5) + (2 x 4)

= 10 + 8 = 18 meters

Question 4.

____________ inches

Answer:

24 inches

Explanation:

Perimeter of a Rectangle = length + width + length + width

P = (2 × length) + (2 × width)

= (2 x 9) + (2 x 3) =18 + 6 = 24 in

Question 5.

____________ yards

Answer:

320 yards

Explanation:

P = 4 x side

= 4 x 80 = 320 yd

Question 6.

____________ meters

Answer: 160 m

Explanation:

Perimeter of a Rectangle = length + width + length + width

P = (2 × length) + (2 × width)

= (2 x 48) + (2 x 32)

= 96 + 64 = 160 m

**Problem Solving**

Question 7.

Mrs. Sanders will put a border around a bulletin board that is 52 inches long and 30 inches wide. How many inches of border will she need?

Answer:

164 inches

Explanation:

Perimeter of a Rectangle = length + width + length + width

P = (2 × length) + (2 × width)

= (2 x 52) + (2 x 30)

= 104 + 60 = 164 inches

Question 8.

A rectangular room is 10 meters wide and 14 meters long. What is its perimeter?

Answer:

48 meters

Explanation:

Perimeter of a Rectangle = length + width + length + width

P = (2 × length) + (2 × width)

= (2 x 10) + (2 x 14) = 20 + 28 = 48 meters

**Lesson Check**

**Fill in the bubble completely to show your answer.**

Question 9.

What is the side length of a square with a perimeter of 60 meters?

(A) 240 meters

(B) 30 meters

(C) 4 meters

(D) 15 meters

Answer:

Option (A)

Explanation:

Perimeter of a Rectangle = length + width + length + width

P = (2 × length) + (2 × width)

= 4 x 60 = 240 meters

Question 10.

Robert wants to put lights around the edge of his yard. The yard is 40 feet long and 25 feet wide. How many feet of lights does he need?

(A) 1000 feet

(B) 130 feet

(C) 100 feet

(D) 160feet

Answer:

Option(B)

Explanation:

Perimeter of a Rectangle = length + width + length + width

P = (2 × length) + (2 × width)

= (2 x 40) + (2 x 25) = 80 + 50 = 130 feet

Question 11.

Each side of a table is 3 meters long. What is the perimeter of the table?

(A) 30 meters

(B) 9 meters

(C) 6 meters

(D) 12 meters

Answer:

Option(D)

Explanation:

Perimeter P = 4 x side

= 4 x 3 = 12 meters

Question 12.

The movie screen at the cinema is 70 feet long and 30 feet wide. What is the perimeter of the screen?

(A) 200 feet

(B) 140 feet

(C) 60 feet

(D) 2100 feet

Answer:

Option (A)

Explanation:

Perimeter of a Rectangle = length + width + length + width

P = (2 × length) + (2 × width)

= (2 x 70) + (2 x 30) =140 + 60 = 200 feet

Question 13.

**Multi-Step** Marcia will make a frame for her picture. The length of the picture is 15 inches. The width is one third of the length. How much wood does Marcia need for the frame?

(A) 18 inches

(B) 40 inches

(C) 30 inches

(D) 45 inches

Answer:

Option(B)

Explanation:

Perimeter of a Rectangle = length + width + length + width

P = (2 × length) + (2 × width)

= (2 x 15) + (2 x 5) = 30 + 10 = 40 inches

Question 14.

**Multi-Step** Greg will build a fence for his yard. The width of the yard is 12 feet. The length of the yard is twice its width. How much fencing will Greg need for his yard?

(A) 60 feet

(B) 48 feet

(C) 24 feet

(D) 72 feet

Answer:

Option(D)

Explanation:

length = 2 x width = 2 x12 = 24 feet

width = 12 feet

Perimeter of a Rectangle = length + width + length + width

P = (2 × length) + (2 × width)

= (2 x 12) + (2 x 24)

= 24 + 48 = 72 feet