# OpenStax_CNX

You are here: Home » Content » Wiskunde Graad 7 » Omtrek

### Lenses

What is a lens?

#### Definition of a lens

##### Lenses

A lens is a custom view of the content in the repository. You can think of it as a fancy kind of list that will let you see content through the eyes of organizations and people you trust.

##### What is in a lens?

Lens makers point to materials (modules and collections), creating a guide that includes their own comments and descriptive tags about the content.

##### Who can create a lens?

Any individual member, a community, or a respected organization.

##### What are tags?

Tags are descriptors added by lens makers to help label content, attaching a vocabulary that is meaningful in the context of the lens.

#### In these lenses

• GETSenPhaseMaths

This module and collection are included inLens: Siyavula: Mathematics (Gr. 7-9)
By: Siyavula

Module Review Status: In Review
Collection Review Status: In Review

Click the "GETSenPhaseMaths" link to see all content selected in this lens.

Click the tag icon to display tags associated with this content.

### Recently Viewed

This feature requires Javascript to be enabled.

### Tags

(What is a tag?)

These tags come from the endorsement, affiliation, and other lenses that include this content.

Inside Collection (Course):

Course by: Siyavula Uploaders. E-mail the author

# Omtrek

Module by: Siyavula Uploaders. E-mail the author

## Memorandum

3.2

250 mm

320 mm

3.3

a) 135 mm

b) 135 mm

c) 104 mm

d) 174 mm

3.4

a) oppervlakte = 2 x (b + d) of oppervlakte = (2 x b) + (2 x d)

b)oppervlakte = 2 x (f+g) of oppervlakte = (2 x f) + (2 x g)

c)oppervlakte = 4 x k

d)oppervlakte = (2 x a) + (2 x e) of oppervlakte = 2 x (a + e)

3.5

Met behulp van stukkie tou of wol en liniaal

3.6

a) 3 100 km

b) 500 km

c) 350 km

d) 15,45 h

38.

a) 42

b) eie antwoord

c) R2,681,70

5.

a) 27

b) 27

c) 39

d) 18

e) 18

f) 9

g) 14

h) 2

i) 12

j) 60

k) 60

l) 64

m) 72

n) 125

o) 108

## Inhoud

### AKTIWITEIT: Omtrek [LU 2.5, LU 4.2, LU 4.3, LU 1.8]

3. PERIMETER

3.1 BELANGRIK om te ONTHOU!

Die omtrek van enige figuur is die totale lengte rondom die figuur, met ander woorde die som van die lengtes van al die sye.Omtrek is dus ’n lengte en word in millimeter, meter of kilometer gemeet.Die akkuraatste manier om die omtrek te bepaal, is om ’n passer en liniaal te gebruik.

3.2 Wat is die omtrek van jou vyf- en aghoek hierbo?

Vyfhoek: ____________________________________________________________

Aghoek: _____________________________________________________________

3.3 Gebruik jou liniaal en bepaal die omtrek van die volgende veelhoeke:

a)

______________________________________

b)

_____________________________________

c)

_____________________________________

d)

_____________________________________

3.4 Werk saam met ’n maat. Lei formules af om die omtrek van die volgende vierhoeke te bepaal:

a) ’n reghoek met lengte b sentimeter en breedte d sentimeter:

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

b) ’n parallellogram met sye f sentimeter en g sentimeter:

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

c) ’n ruit met sye k millimeter:

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

d) ’n vlieër met sye a millimeter en e millimeter:

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

3.5 Hoe sal jy die omtrek van die volgende figure bepaal?

a)

b)

______________________________________________________________

______________________________________________________________

______________________________________________________________

3.6 ’n Graad 7-klas vertrek op ’n toer.

a) Kyk na die meegaande skets en gebruik die skaal om uit te vind hoe ver hulle sal reis.

1 : 100

1 cm = 100km

b) Wat is die werklike afstand van E na B? _____________________________

c) Wat is die werklike afstand van B na D? _____________________________

c) As die bus teen 110 km / h ry, hoeveel uur sal dit neem om van A na F te reis as die bus nie langs die pad stop nie?

____________________________________________________________________

3.8 Die skets toon ’n kamp wat vir skape omhein moet word.

a) As die lengte van die dwarspale 2,7 m is en jy ’n opening van 1,5 m vir ’n hek moet laat, hoeveel regop pale gaan jy nodig hê?

_____________________________________________________________________

_____________________________________________________________________

b) Waar sal jy die opening van die hek laat? Motiveer jou antwoord.

_____________________________________________________________________

_____________________________________________________________________

c) As die pale R63,85 elk kos, hoeveel sal die boer moet spandeer?

_____________________________________________________________________

_____________________________________________________________________

4. Tyd vir selfassessering

 Maak ’n regmerkie in die toepaslike blokkie: Ja Nee Ek kon die oplossings vir die kopkrappers vind Ek kon die reëlmatige vyfhoek teken Ek kon die reëlmatige aghoek teken Ek kan die begrip “omtrek” verduidelik Ek kon die omtrek van die veelhoeke akkuraat bepaal Ek kon die formules vir die omtrek van die volgende veelhoeke aflei en neerskryf: Reghoek Parallelogram Ruit Vlieër Ek kon die afstand wat die Gr. 7’s op hul toer sou aflê, akkuraat volgens skaal bereken Ek kon die aantal pale wat vir die kamp benodig is, korrek bereken

5. Kom ons toets eers jou hoofreken!

Voltooi die volgende so vinnig en akkuraat moontlik:

a) 6 + 7 x 3 = ___________________

b) 6 + (7 x 3) = ___________________

c) (6 + 7) x 3 = ___________________

d) 9 x 6 ÷ 3 = ___________________

e) 9 x (6 ÷ 3) = ___________________

f) 36 ÷ (12 ÷ 3) = ___________________

g) 13 – 5 + 6 = ___________________

h) 13 – (5 + 6) = ___________________

i) 14 – (5 – 3) = ___________________

j) 4 x 3 x 5 = ___________________

k) 5 x (3 x 4) = ___________________

l) 43 = ___________________

m) 32 x 23 = ___________________

n) 53 = ___________________

o) 33 x 22 = ___________________

• Voltooi deur in te kleur:
 Ek het GOED REDELIK SWAK gevaar.

## Assessering

Leeruitkomste 2:Die leerder is in staat om patrone en verwantskappe te herken, te beskryf en voor te stel en probleme op te los deur algebraïese taal en vaardighede te gebruik.

Assesseringstandaard 2.5: Dit is duidelik wanneer die leerder getalsinne oplos of voltooi deur inspeksie of deur ‘n proses van probeer en verbeter, en die oplossings deur vervanging kontroleer (bv. 2 x - 8 = 4).

Leeruitkomste 4:Die leerder is in staat om gepaste meeteenhede, instrumente en formules in ‘n verskeidenheid kontekste te gebruik.

Assesseringstandaard 4.2: Dit is duidelik wanneer die leerder probleme oplos;

Assesseringstandaard 4.3: Dit is duidelik wanneer die leerder probleme oplos deur ‘n verskeidenheid strategieë te gebruik;

Leeruitkomste 1:Die leerder is in staat om getalle en die verwantskappe daarvan te herken, te beskryf en voor te stel, en om tydens probleemoplossing bevoeg en met selfvertroue te tel, te skat, te bereken en te kontroleer.

Assesseringstandaard 1.8: Dit is duidelik wanneer die leerder hoofrekenberekeninge doen wat kwadrate van natuurlike getalle tot minstens 10² en derdemagswaardes van natuurlike getalle tot minstens 5³ behels.

## Content actions

EPUB (?)

### What is an EPUB file?

EPUB is an electronic book format that can be read on a variety of mobile devices.

PDF | EPUB (?)

### What is an EPUB file?

EPUB is an electronic book format that can be read on a variety of mobile devices.

#### Collection to:

My Favorites (?)

'My Favorites' is a special kind of lens which you can use to bookmark modules and collections. 'My Favorites' can only be seen by you, and collections saved in 'My Favorites' can remember the last module you were on. You need an account to use 'My Favorites'.

| A lens I own (?)

#### Definition of a lens

##### Lenses

A lens is a custom view of the content in the repository. You can think of it as a fancy kind of list that will let you see content through the eyes of organizations and people you trust.

##### What is in a lens?

Lens makers point to materials (modules and collections), creating a guide that includes their own comments and descriptive tags about the content.

##### Who can create a lens?

Any individual member, a community, or a respected organization.

##### What are tags?

Tags are descriptors added by lens makers to help label content, attaching a vocabulary that is meaningful in the context of the lens.

| External bookmarks

#### Module to:

My Favorites (?)

'My Favorites' is a special kind of lens which you can use to bookmark modules and collections. 'My Favorites' can only be seen by you, and collections saved in 'My Favorites' can remember the last module you were on. You need an account to use 'My Favorites'.

| A lens I own (?)

#### Definition of a lens

##### Lenses

A lens is a custom view of the content in the repository. You can think of it as a fancy kind of list that will let you see content through the eyes of organizations and people you trust.

##### What is in a lens?

Lens makers point to materials (modules and collections), creating a guide that includes their own comments and descriptive tags about the content.

##### Who can create a lens?

Any individual member, a community, or a respected organization.

##### What are tags?

Tags are descriptors added by lens makers to help label content, attaching a vocabulary that is meaningful in the context of the lens.

| External bookmarks