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Technology

Grade 9

Architectural planning

Module 8

Orthographic projections in drawings

Activity 1:

To be able to distinguish between types of lines that are used in drawings

  • Several different types of line are used to make drawings clearly understandable. . The appearance of a final drawing will depend on the quality of the lines drawn, so it is certainly worth taking care in this area.

Orthographic projection: First Angle and Third Angle Projection. The views in both will be the same but the projection on paper differs. The symbols below are used on drawings to indicate which projection is used.

First angle projection symbol

Third angle projection symbol

  • For this exercise we will only look at First Angle Projection. Your educator will provide you with grid paper which makes it easier for you to draw. If you have drawing equipment it is even better.
  • Always start by drawing the front elevation since this will determine the position of the other views. The plan view is drawn below the front elevation, and the end views on the side furthest away from their position on the front view. Each view only shows two dimensions and together they combine to give a three-dimensional description of the object.
  • The example below illustrates Orthographic views in the first angle projection.

Focus task a

  • Draw a first angle projection of your space case on scale 1:2

END A ELEVATION

FRONT ELEVATION

END B ELEVATION

PLAN

LO 1.5 LO 1.9

Activity 2:

To be able to draw dimension drawings

  • Drawings need to be dimensioned to show what the size of the object is in real live. The dimensions should be the real dimensions of the object. There are international rules for the application of dimensions:
  • All dimensions should be read from the bottom or right-hand side of the paper
  • Limit lines should be drawn out from the object and numbers written above the dimensioning lines stretching between these
  • Smaller measurements should be placed closer to the drawing

Study these examples:

diameters

RADII

POSITION OF HOLES

SIZE OF HOLES

LO 1.15

Assessment

Learning outcomes(LOs)
LO 1
TECHNOLOGICAL PROCESSES AND SKILLS The learner will be able to apply technological processes and skills ethically and responsibly using appropriate information and communication technology.
Assessment standards(ASs)
We know this when the learner:
investigates:1.1 identifies and explains a problem, need or opportunity from a real-life context, and investigates the context, the nature of the need, the environmental situation, and the people concerned;
1.4 uses a variety of available technologies and methods to:
  • locate (e.g. use library referencing system, database searches, indexes);
  • collect (questionnaires, data collection forms, requests for information, information searches, literature surveys);
  • compare;
  • sort;
  • verify;
  • evaluate;
  • store information;
designs:1.5 writes or communicates a short and clear statement or a design brief for the development of a product or system related to a context, problem, need or opportunity that has been identified by self;
1.6 lists product specifications and design specifications and constraints for a solution to an identified problem, need or opportunity based on all of the design key words listed below:
  • people, age, target market, human rights, access;
  • purpose, function, what the product will do;
  • appearance and aesthetics: form, colour, shape, feel;
  • environment: where product will be used or made, impact on the environment in the long and short term;
  • safety: for users and manufacturers;
  • cost, cost of materials, wastage, cost of manufacture, maximum selling price;
  • ergonomics;
  • quality;
  • production;
1.7 generates a range of possible solutions that are significantly different from each other, and that show clear links to the design brief and specifications and constraints;
makes:1.9 develops plans for making that include all of the following:
  • resource lists (e.g. materials lists, tools, people, cost);
  • formal drawings showing dimensions or quantities (e.g. orthographic, oblique or isometric views, sequence drawings, exploded views);
  • manufacturing sequence;

Questions & Answers

the diagram of the digestive system
Assiatu Reply
allimentary cannel
Ogenrwot
How does twins formed
William Reply
They formed in two ways first when one sperm and one egg are splited by mitosis or two sperm and two eggs join together
Oluwatobi
what is genetics
Josephine Reply
Genetics is the study of heredity
Misack
how does twins formed?
Misack
What is manual
Hassan Reply
discuss biological phenomenon and provide pieces of evidence to show that it was responsible for the formation of eukaryotic organelles
Joseph Reply
what is biology
Yousuf Reply
the study of living organisms and their interactions with one another and their environments
AI-Robot
the study of living organisms and their interactions with one another and their environment.
Wine
discuss the biological phenomenon and provide pieces of evidence to show that it was responsible for the formation of eukaryotic organelles in an essay form
Joseph Reply
what is the blood cells
Shaker Reply
list any five characteristics of the blood cells
Shaker
lack electricity and its more savely than electronic microscope because its naturally by using of light
Abdullahi Reply
advantage of electronic microscope is easily and clearly while disadvantage is dangerous because its electronic. advantage of light microscope is savely and naturally by sun while disadvantage is not easily,means its not sharp and not clear
Abdullahi
cell theory state that every organisms composed of one or more cell,cell is the basic unit of life
Abdullahi
is like gone fail us
DENG
cells is the basic structure and functions of all living things
Ramadan
What is classification
ISCONT Reply
is organisms that are similar into groups called tara
Yamosa
in what situation (s) would be the use of a scanning electron microscope be ideal and why?
Kenna Reply
A scanning electron microscope (SEM) is ideal for situations requiring high-resolution imaging of surfaces. It is commonly used in materials science, biology, and geology to examine the topography and composition of samples at a nanoscale level. SEM is particularly useful for studying fine details,
Hilary
cell is the building block of life.
Condoleezza Reply
what is cell divisoin?
Aron Reply
Diversity of living thing
ISCONT
what is cell division
Aron Reply
Cell division is the process by which a single cell divides into two or more daughter cells. It is a fundamental process in all living organisms and is essential for growth, development, and reproduction. Cell division can occur through either mitosis or meiosis.
AI-Robot
What is life?
Allison Reply
life is defined as any system capable of performing functions such as eating, metabolizing,excreting,breathing,moving,Growing,reproducing,and responding to external stimuli.
Mohamed
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Source:  OpenStax, Technology grade 9. OpenStax CNX. Sep 15, 2009 Download for free at http://cnx.org/content/col11071/1.1
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