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Mathematics

Perimeter, area and volume

Educator section

Memorandum

10.

a) Yes, area of all three figures the same

b) area = (half of base) x height

11.1 1 867 km ²

11.2 530 m ²

11.3 9 m by 8 m

12.

13.1

a) 3 and a quarter square cm

b) 5 square cm

13.2 A

14.1

a) 64 cm ²

b) 180 cm ²

c) 81 m ²

d) 200 m ²

14.2

a) 42 m ²

b) 48 cm ²

c) 65 cm ²

d) 64 m ²

Leaner section

Content

Activity: area (brain-teaser) [lo 4.2, lo 1.9, lo 4.5]

10. BRAIN-TEASER!

A farmer divides his land as follows among his three children:

a) Was the farmer fair? __________________________ Motivate your answer:

_____________________________________________________________________

_____________________________________________________________________

b) From the above example, can you work out a formula that we use to determine the area of a triangle?

_____________________________________________________________________

11.1 Calculate the area of the farmer’s farm without the dam.

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

11.2 What is the area of this lucerne camp on the farmer’s farm?

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

11.3 The farmer wants to fence a rectangular camp with an area of 72m2. Problem: The perimeter must be kept to the minimum (because of the cost of the wire). What will the measurements of the camp be?

_____________________________________________________________________

12. A rectangular rugby field has a length of 110 m and a breadth of 60 m. What will it cost to plant grass which costs R6,45 per square metre?

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

13.1 If each square is 1 cm2, what is the area of the shaded section?

a)

_____________________________________

b)

_____________________________________

13.2 Which figure has the biggest area: A or B?

A

_____________________________________

B

_____________________________________

14. BRAINTEASERS!

  • Work with a friend.

14.1 Can you determine the area of the shaded parts of each figure?

a)

_____________________________________

_____________________________________

_____________________________________

b)

_____________________________________

_____________________________________

_____________________________________

c)

_____________________________________

_____________________________________

_____________________________________

d)

_____________________________________

_____________________________________

_____________________________________

14.2 Calculate the areas of the following figures?

a)

_____________________________________

_____________________________________

_____________________________________

_____________________________________

b)

_____________________________________

_____________________________________

_____________________________________

_____________________________________

c)

_____________________________________

_____________________________________

_____________________________________

_____________________________________

d)

_____________________________________

_____________________________________

_____________________________________

_____________________________________

15. CLASS DISCUSSION

  • Let us discuss the following as a class:

15.1 Your school wants to build a new computer centre. The two possible plans that have been drawn up look like this:

A

B

  • Discuss:

a) Which plan would use the most bricks? Why?

b) Which plan would accommodate the most computers? Motivate.

c) Which plan will be the most expensive to build? Why?

15.2 A plan for a swimming pool for the school has also been drawn up:

a) What will happen to the area if the perimeter stays the same, BUT:

(i) the length increases and the breadth decreases?

(ii) the length decreases and the breadth increases?

b) When would the swimming pool have a maximum area?

Assessment

Learning Outcome 4: The learner will be able to use appropriate measuring units, instruments and formulae in a variety of contexts.

Assessment Standard 4.2: We know this when the learner solves problems;

Assessment Standard 4.5: We know this when the learner calculates, by selecting and using appropriate formulae.

Learning Outcome 1: The learner will be able to recognise, describe and represent numbers and their relationships, and to count, estimate, calculate and check with competence and confidence in solving problems.

Assessment Standard 1.9: We know this when the learner uses a range of techniques to perform calculations.

Questions & Answers

Application of nanotechnology in medicine
what is variations in raman spectra for nanomaterials
Jyoti Reply
I only see partial conversation and what's the question here!
Crow Reply
what about nanotechnology for water purification
RAW Reply
please someone correct me if I'm wrong but I think one can use nanoparticles, specially silver nanoparticles for water treatment.
Damian
yes that's correct
Professor
I think
Professor
what is the stm
Brian Reply
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
Rafiq
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
Damian
How we are making nano material?
LITNING Reply
what is a peer
LITNING Reply
What is meant by 'nano scale'?
LITNING Reply
What is STMs full form?
LITNING
scanning tunneling microscope
Sahil
how nano science is used for hydrophobicity
Santosh
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
Rafiq
what is differents between GO and RGO?
Mahi
what is simplest way to understand the applications of nano robots used to detect the cancer affected cell of human body.? How this robot is carried to required site of body cell.? what will be the carrier material and how can be detected that correct delivery of drug is done Rafiq
Rafiq
if virus is killing to make ARTIFICIAL DNA OF GRAPHENE FOR KILLED THE VIRUS .THIS IS OUR ASSUMPTION
Anam
analytical skills graphene is prepared to kill any type viruses .
Anam
what is Nano technology ?
Bob Reply
write examples of Nano molecule?
Bob
The nanotechnology is as new science, to scale nanometric
brayan
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Damian
Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
Renato
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
?
Kyle
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
Adin
why?
Adin
what school?
Kyle
biomolecules are e building blocks of every organics and inorganic materials.
Joe
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
research.net
kanaga
sciencedirect big data base
Ernesto
Introduction about quantum dots in nanotechnology
Praveena Reply
hi
Loga
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
Bharti
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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Source:  OpenStax, Mathematics grade 7. OpenStax CNX. Sep 16, 2009 Download for free at http://cnx.org/content/col11075/1.1
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