4. Area is the amount of surface space
that a flat object has.
Area is measured in square units.
1 unit
1 unit
1 unit
1 unit
5. When you measure the amount of
carpet to cover the floor of a room,
you measure it in square units.
Would the area of your bedroom
or the area of your house be
greater?
You’re right! The area of your house is
greater than the area of your bedroom.
6. Area = 15 square units
Lets find the area of this surface if
each square is equal to one unit.
Count the number of squares.
1 2
3
4 5 6 7 8
9 10 11 12 13 14
15
7. Count the number of
green squares to
determine the area of this
surface. What is the
area?
The area is equal
to 9 square units.
1
5
2
4
7
3
6
8 9
8. Two neighbors build swimming pools. This
is what the pools look like.
Family A Family B
Which family has the pool with the bigger
swimming area?
Let’s do these problems
together.
9. The area of Family A’s pool is?
Family A
Family B
8 square units.
7 square units
The area of Family B’s pool is?
Therefore, Family A has the pool with
the bigger swimming area.
10. Formulas in finding the
area of plane figures
Area of a square:
A = s x s or s²
Area of a rectangle:
A = L x W
Where s is the side of
the square.
S
Where L is the length while
W is the width of the
rectangle.
W
L
11. Formulas in finding the
area of plane figures
Area of a square:
Area of a rectangle:
4cm
3cm
5cm
EXAMPLE:
A = s x s or s²
A = 4 x 4 or 4²
A = 16 cm²
A = L x W
A = 5 x 3
A = 15 cm²
12. Formulas in finding the
area of plane figures
Area of a parallelogram:
A = B x H
Area of a triangle:
A = ½ x B x H
B B
H
Where B is the base while H
is the height of the
parallelogram.
H
Where B is the base while H
is the height of the triangle.
13. Formulas in finding the
area of plane figures
Area of a parallelogram:
Area of a triangle:
A = ½ x B x H
7m
8cm
2m 3cm
EXAMPLE:
A = 7 x 3
A = B x H
A = 21 m²
A = ½ x 8 x 3
A = ½ x 24
A = 12 cm²
14. Formulas in finding the
area of plane figures
Area of a trapezoid:
A = ½ x(b1 + b2) x H
Area of a circle:
A = 𝜋 𝑥 𝑟²
B
Where B is the base while H
is the height of the
parallelogram.
Where r is the radius of the
circle.
H r
Where 𝜋 = 3.14
B
15. Formulas in finding the
area of plane figures
Area of a trapezoid:
A = ½ x(b1 + b2) x H
6cm
3cm
EXAMPLE:
4cm A = ½ x(4 + 6) x 3
A = ½ x(10) x 3
A = 5 x 3
A = 15 cm²
16. Formulas in finding the
area of plane figures
Area of a circle:
A = 𝜋 𝑥 𝑟²
5 cm
EXAMPLE:
A = 3.14 𝑥 5²
A = 3.14 𝑥 25
A = 78.50 cm²
17. Formulas in finding the
area of plane figures
Area of a circle:
A = 𝜋 𝑥 𝑟²
8 cm
EXAMPLE:
A = 3.14 𝑥 4²
A = 3.14 𝑥 16
A = 50.24 cm²
21. Finding the area of
composite figures
Is made up of several simple geometric
figures.
Is formed from two or more figures.
COMPOSITE FIGURES
22. Subdivide the figure into simpler
shapes.
Find the areas of each figure then add
them up.
To find the area of a shaded region,
you need to subtract the areas.
TO FIND THE AREA OF A
COMPOSITE FIGURES:
23. 10cm
8cm
8cm
2cm
4cm
4cm
Area =
4 x 10
40cm2
Area =
4 x 8
32cm2
Total area = 40 + 32
= 72 cm
2
EXAMPLES:
Example #1: Find the area of the composite figure.
24. Example #2: Find the area of the
composite figure.
Area of square:
A = lw = 7(7) = 49 yd2
Total area of figure: Add up
areas of 2 triangles and
square:
A = 2(14) + 49
= 28 + 49 = 77 yd2.
Area of 1 triangle:
A = ½ bh
A = ½ (7)(4)
A = ½ (28)
A = 14 yds2
EXAMPLES:
25. Example #3: Find the area of the
figure. 3 ft.
Total area of figure:
Add areas of square and
semicircle:
A = 36 + 14.13 ft2
A = 50.13 ft²
EXAMPLES:
Area of square:
A = SxS = 6(6) = 36 ft2
Area of circle:
A = r2
A = 3.14(3)2 = 3.14(9)
A = 28.26 ft2
Area of semicircle =
½ (28.26) = 14.13 ft2
26. 8cm
area = 64 – 50.24
= 13.76 cm
2
Example #4:Find the area of the
shaded region of the figure.
A = 3.14 𝑥 4²
A = 3.14 𝑥 16
A = 50.24
A = s x s or s²
A = 8 x 8 or 8²
A = 64 cm²
cm²
EXAMPLES:
Area of square:
Area of the circle:
Area of the shaded region:
27. • What is its radius?
• Diameter = Length of square
= = 8 ft.
• Radius = ½ (8) = 4 ft.
• Area of circle:
• A = r2
• A = 3.14(4)2 = 3.14(16) ft2.
• A = 50.24 ft²
64
Area of shaded region
A = 64 – 50.24ft2.
A = 13.76ft²
d = 8 ft.
EXAMPLES:
Example #5: Find the area of the
shaded region if the area of the
square is 64 ft2.
33. 20
cm
A = ½bh
A = ½ 30(20)
A = 15(20)
A = L(W)
A = 30 x 20
A = 600 cm²
cm²
A = 300
Area of rectangle
Area of triangle
Area of the shaded region:
A = 600 – 300
A = 300 cm²
34. 3cm
A = 3.14 𝑥 3²
A = 3.14 𝑥 9
A = 28.26
A = s x s or s²
A = 2 x 2 or 2²
A = 4 cm²
cm²
Area of circle
Area of square
Area of the shaded region:
A = 28.26 – 4
A = 24.26cm²
35. REMINDER!!!
STUDY FOR A DIGITAL
QUIZ ON FRIDAY.
MEASURING AREA AND
SPEED, DISTANCE AND TIME
