47777
Mathematics
Quarter 4 – Module 1
Area of Plane Figures
Mathematics – Grade 4
Alternative Delivery Mode
Quarter 4 – Module 1: Area of Plane Figures
First Edition, 2020
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Published by the Department of Education
Secretary: Leonor Magtolis Briones
Undersecretary: Diosdado M. San Antonio
Development Team of the Module
Writer: Cirila P. Encio
Editors: Ivy C. Añosa PhD
Estrella I. Peliño
Management Team: Bianito A. Dagatan EdD, CESO V
Schools Division Superintendent
Casiana P. Caberte PhD
Assistant Schools Division Superintendent
Felix C. Galacio Jr. PhD
EPS, Mathematics
Josephine D. Eronico PhD
EPS, LRMDS
Printed in the Philippines by Schools Division of Bohol
Department of Education – Region VII, Central Visayas
Office Address: 0050 Lino Chatto Drive Barangay Cogon, Tagbilaran City,
Bohol
Telefax: (038) 501 – 7550
Tel Nos. (038) 412 – 4938; (038) 411-2544; (038) 501 – 7550
E-mail Address: depedbohol@deped.gov.ph
Learning Competencies:
Finds the area of irregular figures made up of squares and rectangles using sq. cm
and sq. m. M4ME-Iva-55
Finds the area of a parallelogram using sq. cm and sq. m. M4ME-IVb-58
Finds the area of a triangle using sq. cm and sq. m. M4ME-IVb-58
At the end of the lesson, you are expected to:
Find the area of an irregular figure;
Find the area of a parallelogram; and
Find the area of a triangle.
Lesson
Finding the Area of an Irregular Figure
1
What is it
To find the area of an irregular shape that is made up of squares and rectangles, we have
to follow these steps:
1. Divide or cut the figure into squares and rectangles;
2. Find the area of each square or rectangle made;
3. Add the areas of the squares and/or rectangles made to find the area of the irregular
figures; and
4. Express the area in sq cm (cm 2 ) or sq m ( m 2)
Example:
This irregular figure at the right
can be divided or cut into squares
and rectangles in two ways:
Figure 1
To find the area in figure 1, you do these:
Area of square A: 4 cm x 4 cm = 16 sq cm or cm 2
Area of square B: 4 cm x 4 cm = 16 sq cm or cm 2
Area of rectangle C: 4 cm x 12 cm = 48 sq cm or cm 2
Add the areas: 16 + 16 + 48 = 80sq cm or cm 2
Figure 2
To find the area in figure 2, you do these:
Area of Rectangle A: 4 cm x 8 cm = 32 sq cm or cm 2
Area of Rectangle B: 4 cm x 8 cm = 32 sq cm or cm 2
Area of Square C: 4 cm x 4 cm = 16 sq cm or cm 2
Add the areas: 32 + 32 + 16 = 80 sq cm or cm 2
So, the area of the irregular figure is 80 sq cm or m 2
What’s More
Direction: Find the area of each figure.
1. 2.
Lesson
Finding the Area of a Parallelogram
2
What is it
To get the area of a parallelogram, we used this formula:
Area of a parallelogram = base x height
If A is the area of the parallelogram, b is the base, and h is the height, then A = b x h
and is expressed in terms of square units.
Example:
A vegetable garden has the shape of a parallelogram. It has a base of
6 meters and a height of 3 meters. What is the area of the garden?
Area of a parallelogram = base x height
A=bxh
=6mx3m
A = 18 m 2
So, the area of the garden is 18 m 2
What’s More
Direction: Find the area of the parallelogram using the formula.
2.
Lesson
Finding the Area of a Triangle
3
What is it
The area of a triangle with a given base (b) and height (h) can be
solved by the formula:
Area of triangle = one half of the base x height or
1
A = ( b x h) and is expressed in terms of square units.
2
Example:
Maris has a flower garden. The garden is triangular in shape. The length of the base is
8 meters, and the height is 6 meters. What is the area of the garden?
To find the area of the garden, we follow this formula:
1
A = ( b x h)
2
1
= ( 8 m x 6 m)
2
48
=
2
A = 24 m 2 So, the area of the garden is 24 m 2
What’s More
Direction: Find the area of each triangle using the formula.
Assessment
Direction: Find the area of the following figures. Write the letter of the correct answer.
1. a. 140 cm 2 b. 144 cm2
c. 150 cm 2 d. 154 cm2
2. a. 400 cm 2 b. 500 cm2
c. 600 cm2 d. 700 cm2
3.
a. 150 m 2 b. 250 m 2
c. 350 m2 d. 450 m 2
4. a. 47 dm b. 47 d m2
h=14 dm
c. 462 dm d. 462 d m 2
b = 33 dm
a. 15m b. 15 m 2
5.
h=9m
c. 54 m d. 54 m 2
b=6m
6. a. 80 cm b. 80 cm 2
h = 8 cm c. 810 cm d. 810 cm2
b = 10 cm
7. a. 75 cm b. 75 cm 2
10 cm c. 150 cm c. 150 cm 2
15 cm
6m
8. a. 24 m b 24 m2
8m
c. 48 m d. 48 m2
9. a. 150 cm b. 150 cm2
15 cm
c. 300 cm d. 300 cm2
20 cm
10. a. 12 m b. 12 m2
6m c. 24 m d. 24 m 2
4m
Answer Sheet
Name: __________________________________________________________
Grade & Section: ________________ Score: _______
Quarter 4 – Module 1
Lesson 1
What’s More
1. 2.
Lesson 2
What’s More
1. 2.
Lesson 3
What’s More
1. 2.
Assessment
1. 2. 3. 4. 5.
6. 7. 8. 9. 10.
