TataKelola dan KamSiber Kecerdasan Buatan v022.pdf
Area and perimeter_10_r5
1. Starter
• On whiteboards, write down as many units of
LENGTH as you can
• Write down as many units for AREA as you can
EXTENSION:
What is the perimeter of
this rectangle?
2. Perimeter 25/02/2013
Learning Objectives:
Know the key words for perimeter and
the units used
Able to calculate the perimeter of a
rectangle
Able to calculate the perimeter of a
compound shape
3. Perimeter
• Perimeter: The distance around the outside of
a shape
• To calculate the perimeter, you add together
all the sides of a shape
4. Perimeter
10cm
• Example:
3cm
P = 10 + 3 + 10 + 3
P = 26cm
5. Perimeter
• Calculate the perimeter of the following
1cm
rectangles:
12cm
EXTENSION:
9cm b) Can you
a) 4cm calculate the
area of these
rectangles?
5m
c) d) 5cm
5cm
6m
7. Perimeter
10m Can I calculate the
perimeter of this
shape?
15m
I need to find the
21m length of the
25m
missing sides first.
P = 10 + 15 + 21 + 10 + 31 + 25
10m Now I can calculate
P = 112m the perimeter by
adding up the all the
31m sides.
8. Perimeter
• Example:
10cm Perimeter = 5 +
5cm as it is a
5cm rectangle
10 + 5 + 3 + 9 + 4
+9+3
3cm 3cm
Perimeter = 48cm
9cm 9cm
10 – 3 – 3 = 4cm
10. Perimeter 25/02/2013
Learning Objectives:
Able to calculate the perimeter of a
rectangle
Able to calculate the perimeter of a
compound shape
Able to calculate the area of a
rectangle
12. Area
• How can I calculate the area of this rectangle?
• Count the squares
inside the shape
• Multiply the width
by the length
13. Area of a rectangle
• Area of a rectangle = length x width
Area = 4 x 12
4cm
Area = 48cm2
12cm
14. Starter
• How many rectangles can you design that
have an area of 24cm2?
• Do the sides have to be whole numbers?
15. Area of Triangles 25/02/2013
Learning Objectives:
• Able to calculate the area of a rectangle
• Able to calculate the area of a triangle
• Able to calculate the area of a compound
shape
16. Area of Triangles
Height
Base
• Area of a triangle = ½ x base x height
= ½bh
17. Area of a Triangle
• Calculate the area of this triangle.
4cm
12cm
Area = ½ x 4 x 12
= 24cm2
18. Area of Triangles
• Find the area of the shaded triangle BCD.
5cm 4cm
A B C
6cm
Area of ACD = ½ x 9 x 6
= 27cm2
11cm
Area of ABD = ½ x 5 x 6
D = 15cm2
Area of BCD = 27 – 15
= 12cm2
20. Starter
• Complete the worksheet in your workbook
– Show all your working out
– Remember to use the correct units!
21. Grade D
Area of Triangles 25/02/2013
Learning Objectives:
• Able to calculate the area of a right angled
triangle
• Able to identify the perpendicular height of a
triangle
• Able to calculate the area of any triangle
26. Grade D
Area of Triangles 25/02/2013
Learning Objectives:
• Able to calculate the area of a right-angled
triangle
• Able to calculate the area of other
triangles
• Able to calculate the area of a parallelogram
28. Some work…
• In your workbooks, work through pages 65
and 66.
29. Home Learning
• Complete the worksheet in your books
• Show all working out
• DUE: Monday 19th September
30. Starter
• Match the shape to the correct area and
perimeter.
• There is one perimeter and one area that
don’t have a shape. Draw the shape to match
the perimeter and area on the blank card.
31. Parallelograms and Trapezia
Grade D 25/02/2013
Learning Objectives
• Able to calculate the area of triangles
• Able to calculate the area of parallelograms
and trapezia
32. Area of a Parallelogram
Area of Parallelogram = base x perpendicular
height
height
Base
Area = 6 x 12
9cm
6cm
= 72cm2
12cm
33. Area of a Trapezium
a
h
b
Area of Trapezium = ½ (a + b) x h
a and b are the parallel sides
35. Area of Compound Shapes
Grade D 25/02/2013
Learning Objectives:
• Able to calculate areas of trapezia
• Able to split up a compound shape
• Able to find the area of a compound
shape
36. Compound Shapes
• To find the area of compound shapes, split
them up into their composite shapes.
• Find the area of each shape, then add them
together
37. Compound Shapes
8cm
Area A = 8 x 5
A 5cm
= 40cm2
Area B = 11 x 2
= 22cm2
B 11cm
Total Area = 40 + 22
= 62cm2
2cm
41. Grade D/C
Circles 25/02/2013
Learning Objectives:
• Able to calculate the radius and diameter
of a circle
• Able to use a calculator to find the
circumference of a circle
• Able to calculate the area of a circle
42. Circles
• Radius – distance
from centre to
outside of a circle
• Diameter –
distance from one
side of the circle to
the other, passing
through the centre
44. Circles
• Circumference – the distance around the
outside of a circle.
• You are going to investigate the relationship
between the circumference and the diameter.
45. Circles
1) Measure the circumference and diameter of
the objects and record them in the table.
2) Divide the circumference by the diameter.
Write your results in the table
3) Can you spot the common link?
47. Starter
Calculate the area of each of the following shapes.
13cm
6cm 7cm
5cm 7cm
12cm
11cm
4cm
15cm
6cm
18cm
48. Grade D/C
Circles 25/02/2013
Learning Objectives:
• Able to calculate the radius and diameter
of a circle
• Able to use a calculator to find the
circumference of a circle
• Able to calculate the area of a circle
49. Circles
• This relationship between the circumference and
diameter is called ‘pi’
• The symbol for pi is ∏
• ∏ = 3.1415926….
• We often use 3.14 as an approximation
• It is found on calculators
52. Circles
Find the circumference of the
circle.
7cm
C=2x∏x7
C = 14 x ∏
C = 43.98cm (2dp)
53. Starter
• Calculate the area of • Calculate the
this trapezium circumference of this
4cm
circle
11cm
6cm 8cm
10cm
54. Grade D/C
Circumference 25/02/2013
Learning Objectives:
• Able to calculate the radius and diameter
of a circle
• Able to use a calculator to find the
circumference of a circle
• Able to calculate the area of a circle
55. Circles
If I want to find the circumference of these circles, which formula
should I use?
6cm
C=2x∏xr C=∏xd
C=2x∏x6 C = ∏ x 14
C = 12 x ∏ C = 43.98 (2dp)
C = 37.7cm (1dp)
57. Starter
• On your whiteboard, calculate the
circumference of the following shapes.
10cm
9cm
58. Grade C
Area of Circles 25/02/2013
Learning Objectives:
• Able to calculate the circumference of a circle
• Able to calculate the area of a circle given
the radius
• Able to calculate the area of a circle given
the diameter