(2) Right Angled Triangle

It’s Angular (2)
Right Angled Triangle
This is the second in a series of activities to relate the theory of geometric shape to the
design of BLOODHOUND SSC to pupils to pupils aged 9-14.
When designing BLOODHOUND SSC every line, curve and shape has a job to
do in order for this incredible machine to break the World land Speed record
and attain 1,000 mph.
Learning Objectives
To understand that right angled triangles when used in construction design, form strong,
aerodynamic, directional shapes
Programme of Study at Key Stage 2
This is a Mathematics activity including strong links to English, Science and D&T to view click here
Differentiation
 All children to be able to draw a right angled triangle
 Most children to be able to draw a right-angled triangle and to recount the rules governing
such triangles
 Some children will be able to draw a right-angled triangle and describe its special qualities,
regular shape and the application of Pythagoras’ Theorem..
Resources
300 m ruler
Sharp pencil
Protractor
Thick card
Scissors
Paper glue
Sticky tape
Internal Angle
Vertex
External Angle
Vocabulary
Right Angle
Sides
Hypotenuse
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Apex
Degrees
It’s Angular (2)
Right Angled Triangle
Geometric Discussion
1.
2.
3.
4.
5.
A right-angled triangle has three sides of variable length.
The sum of the internal angles of a triangle equal 180°.
The angle opposite the hypotenuse is 90°
The hypotenuse is the side opposite the right angle of the triangle.
A right-angled triangle has one vertex from the mid of the right angle to the centre
of the hypotenuse.
6. Try drawing a right angled triangle using a ruler and a protractor. Remember that the
angle B, marked in blue is a right angle.
7. Label the side that forms the hypotenuse.
8. Two and a half thousand years ago a very clever man with a long beard named
Pythagoras developed his theory about right angled triangles.
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It’s Angular (2)
Right Angled Triangle
9. He stated that if you draw, using our example, a square on the sides A-B and B-C you
will be able to work out the length of side A-C. Clever? You try it!
10. So what is the length, X of Side A-C? Well 60 x 60 = 3,600 and 40 X 40 = 1,600. Add them
together and you get 5,200 mm2.
11. This means that the square on hypotenuse A-C is 5,200 mm2. The length X is therefore the
square root of 5,200 mm2 (
)
12. The answer is ... well work it out in your head or with a calculator. Using my seven times
table I know that the answer will be roughly 70. How did I do that? Why not discuss this as a
class?
Now what does this have to do with BLOODHOUND SSC? Well, Ron Ayers and his team of designers
have used a right angle shape for the tail fin of the car. Why? Look at the front edge of the tail.
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It’s Angular (2)
Right Angled Triangle
13. The front edge of the tail is the hypotenuse of a right angled triangle.
14. In fact if you extend the hypotenuse A-C you will find that it bisects the centre of the car
approximately one third along the length of the car. The reasons for this are complex, but
enough to say that this is the most stable arrangement.
What Went Well?


Did you find drawing the triangle easy?
Did you have the right tools to do the job?



Did you find it easy to work out length X?
Do you understand the way that triangles can be used to design machines?
Would you like to make a BLOODHOUND SSC tailfin? Click here
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It’s Angular (2)
Right Angled Triangle
BLOODHOUND SSC Tailfin Template
Cut out and glue together
Cut out and glue together
Cut out and glue together
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It’s Angular (2)
Right Angled Triangle
Discovery sheet
Aim:
To construct BLOODHOUND S.S.C. Tailfin.
Two sheets of 160g-1m
card
Paper glue, Pritt Stick
type.
300mm ruler
BLOODHOUND SSC
Tailfin Template
What you plan to do:
What did you find easy to do and what was difficult to do?
What would you change if you repeated the construction of the tailfin?
Conclusion
Explain what happened and say What Went Well in making your BLOODHOUND SSC Tailfin
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It’s Angular (2)
Right Angled Triangle
Programme of study at Key Stage 2
D&T
Developing planning and communicating
ideas
Working with tools, equipment, materials
and components to make quality products
Evaluating processes and products
Knowledge and understanding of materials
& components
Breadth of Study
Mathematics Using and applying shape, space and
measures
Communication
Reason
Properties of shapes
Measures
Science
Sc1
2a, 2b, 2c, 2d, 2e, 2f
3a, 3b, 3c
4a, 4b, 4c
5a, 5b, 5c
1a, 1b, 1c, 1d
1e, 1f, 1g
1h
2a, 2b, 2c, 2d
4a, 4b, 4c
Ideas and Evidence in Science
Investigative Skills
Obtaining & Presenting Evidence
Considering Evidence
Forces & Motion
Knowledge, skills and understanding
Communication
Ideas and Evidence in Science
Investigative Skills
Obtaining & Presenting Evidence
Considering Evidence
1a, 1b.
2a, 2b, 2c, 2d
2e, 2f, 2g, 2h.
2i, 2j, 2k, 2l, 2m.
2a, 2b, 2c, 2d, 2e.
1a, 1b, 1c, 1d.
2a, 2b.
1a, 1b.
2a, 2b, 2c, 2d
2e, 2f, 2g, 2h.
2i, 2j, 2k, 2l, 2m.
En1
Speaking & Listening
1a, 1b, 1d
En3
Composition
1a, 1e
Sc4
Breadth of Study
Sc1
English
1a, 1b, 1c,
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