TOPIC
Strand: Shapes and Space
2D Shapes
22
527
528
529
531
1.
2.
3.
4.
5.
6.
Identify the properties of the circle.
Construct a circle of a given radius or diameter.
Tessellate combinations of 2D shapes.
Use 2D shapes and properties to solve problems.
This is the first time that the properties of the circle are introduced into the curriculum.
Identifying, describing and classifying 2D shapes.
Exploring, describing and comparing the properties of 2D shapes.
Constructing and drawing 2D shapes.
Identifying the use of 2D shapes in the environment.
Solving and completing practical tasks involving 2D shapes.
1. Applying and problem-solving: Analyse problems involving circles and plan an approach to
solving them; apply the concept of radius and diameter in a variety of contexts.
2. Integrating and connecting: Recognise mathematics in the environment; connect informally
held ideas on the properties of a circle with formal concepts and processes for constructing a
circle.
3. Reasoning: Make informal deductions on the nature of the circle; investigate mathematical
patterns that can be made with circles.
4. Implementing: Execute standard procedures for constructing a circle.
5. Understanding and recalling: Understanding and recalling facts on the properties of a circle.
Compasses, rulers
Circle, angles, symmetry, diagonals, parallel, perpendicular, polygon, regular,
irregular, quadrilateral, degrees, vertices, compass, circumference, radius, radii,
diameter, arc, chord, sector, quadrant, semicircle, area
1. It is no longer appropriate to refer to the circumference of a circle as a ‘side’. A
‘side’ should be used to refer to the straight edges of a polygon.
88
2. High achievers may be encouraged to discover pi (3·14) by measuring the circumference with a
piece of string and then dividing it by the length of the diameter.
Loop game:
Doubles and halves: This will help the children when finding the radius while knowing the diameter.
If the diameter is 22cm what is the radius? Apply this to other numbers.
If the radius of a circle is 2cm, 12cm, 10cm, what will its diameter be? What will the circumference
be?
1. Compare and contrast the circle with other 2D shapes: square, triangle, pentagon, semicircle,
and trapezium.
2. Investigate the incidence and history of crop-circles at:
http://www.coolmath.com/lesson-geometry-of-crop-circles-1.html.
3. Learn about the invention of the wheel.
1. Name each of the shapes.
2. Are all of the shapes 2D shapes? Are all the shapes polygons? Which shapes are quadrilateral
polygons? Which shapes are triangular polygons? Sort the shapes using the diagram given.
3. Where does the circle fit on this diagram?
Lower attainers:
1. Activities on constructing a circle with a given radius or diameter.
2. Labelling the parts of a circle.
3. Calculating the radius and diameter of a circle when only one of them is known.
Higher attainers:
‘Challenge Yourself’ activity on page 140 and Activity A on page 141 will provide a stretch for higher
attainers.
Topic
22
1. Construct a circle with
(a) Radius of 4cm
(b) Diameter of 6cm
(c) Radius of 2cm
(d) Diameter of 9cm
2. What is the length of the radius when
(a) The diameter is 8cm. Radius = ____ cm
(b) The diameter is 10cm. Radius = ____ cm
(c) The diameter is 11cm. Radius = ____ cm
3. What is the length of the diameter when
(a) Radius is 2cm. Diameter = ____ cm
(b) Radius is 9cm. Diameter = ____ cm
(c) Radius is 4 12 cm. Diameter = ____ cm
4. Label the parts of a circle.
(a)
(e)
(b)
(d)
Name: _______________________________________
Date: ___________________
© Folens Photocopiables
(c)
89
Fractions: Fractional part of a circle (quadrant, semicircle)
Measures: Area of a 2D shape
Length: Circumference of a circle
Visual arts: Construction of crop circles, patterns with tessellating circles
History: Continuity and change, the invention of the wheel and the development of transport
At the end of this unit children should be able to construct a circle of a given radius or diameter
using a compass. They should also be able to describe the properties of the circle using the
following terms: diameter, radius, circumference, chord, arc, sector and quadrant.
In the environment children should be able to describe and compare the use of 2D shapes, for
example, in the context of architecture, art and industrial design. They should be encouraged
to utilise their knowledge of properties in relation to lines, angles, diagonals, symmetry, and
tessellations when describing 2D shapes.
Notes
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________