# Connexions

You are here: Home » Content » Mathematics Grade 8 » Classifiying, measuring and constructing angles

### 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 collection is included inLens: Siyavula: Mathematics (Gr. 7-9)
By: Siyavula

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

# Classifiying, measuring and constructing angles

Module by: Siyavula Uploaders. E-mail the author

## CLASSIFYING , MEASURING AND CONSTRUCTING ANGLES

1. How do you construct (draw) any size of angle?

To do this, you require the following:

compasses, protractor and ruler

General: construction of e.g. ABˆCABˆC size 12{A { hat {B}}C} {} = 60°

1. a) Start by drawing a line

b) Make a mark on the line

d) Read from the 0º on the right-hand side to the desired degree

e) Name your angle correctly [e.g. ABˆCABˆC size 12{A { hat {B}}C} {} = 60° or Bˆ1Bˆ1 size 12{ { hat {B}} rSub { size 8{1} } } {} = 60° ]

2. How would you go about constructing an angle of, for example, 330º if the protractor can measure only angle sizes up to 180º?Write down your plan below:

3. Construct the following angles and classify each and indicate the limits of degrees. E.g. 60° -- acute angle(classification) --- 0° < x < 90° (limits of°)Limits of ° are read as follows: x greater than 0° and smaller than 90°

 Angle Sketch Classification(kind of angle) Limits of ° 3.1 PQˆRPQˆR size 12{P { hat {Q}}R} {} = 75° 3.2 ABˆCABˆC size 12{A { hat {B}}C} {} = 125° 3.3 HFˆGHFˆG size 12{H { hat {F}}G} {} = 325° 3.4 CDˆECDˆE size 12{C { hat {D}}E} {} = 180° 3.5 KLˆMKLˆM size 12{K { hat {L}}M} {} = 90° 3.6 RSˆTRSˆT size 12{R { hat {S}}T} {} = 360°

HOMEWORK ASSIGNMENT 1

1. There are angles all around you....Determine the size of each of the angles indicated (with the aid of your protractor),write down the size of the angle concernedand classify it.

1.1

1.2

1.3

1.4

1.5

1.6

1.7

1.8

1.9

1.10

1.11

1.12

1.13

1.14

1.15

1.16

2. Construct the following angles by using your ruler and protractor.

2.1 A watch with an angle of 45º between the two numbers.

2.2 A sun bed with an angle of 160°

2.3 A helicopter dropping at an angle of 35º with horizontal.

2.4 A reading lamp with angles 115º and 65º.

## Memorandum

CLASSWORK ASSIGNMENT 1

2. 3600 – 3300 = 300

size 12{ and } {} Construct 300

• size 12{ and } {}Acute angle 00 size 12{∠} {}Q size 12{∠} {} 900
• size 12{ and } {}Obtuse angle 900 size 12{∠} {}B size 12{∠} {} 1800
• size 12{ and } {}Reflexangle 1800 size 12{∠} {}F size 12{∠} {} 3600
• size 12{ and } {}Straight (flat) angle D = 1800
• size 12{ and } {}Right angle L = 900
• Angle of rotation S = 3600

### HOMEWORK ASSIGNMENT 1 AND 2

• Acute size 12{∠} {}
• Obtuse size 12{∠} {}
• Obtuse size 12{∠} {}

1.4 Reflex size 12{∠} {}

• Obtuse size 12{∠} {}
• Acute size 12{∠} {}
• Acute size 12{∠} {}
• Acute size 12{∠} {}
• Acute size 12{∠} {}
• Acute size 12{∠} {}
• Acute size 12{∠} {}
• Reflex size 12{∠} {}
• Acute size 12{∠} {}
• Obtuse size 12{∠} {}
• Obtuse size 12{∠} {} and Acute size 12{∠} {}
• Obtuse size 12{∠} {} and Acute size 12{∠} {}

CLASSWORK ASSIGNMENT 2

1.a) Acute angle

b) one right angle

c) one obtuse angle

• acute-angled
• right-angled / acute-angled
• obtuse-angled
• right-angled

## Content actions

PDF | 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