Presentation on theme: "Once I was asked by my teacher to draw a picture of a CD. I grabbed a ruler, measured out all dimensions (width and height) carefully. Then I drew the."— Presentation transcript:
Once I was asked by my teacher to draw a picture of a CD. I grabbed a ruler, measured out all dimensions (width and height) carefully. Then I drew the CD based on those dimensions. This is was an easy task. Then my teacher asked me to draw my bedroom. I thought this would be difficult but once the teacher explained to me about scale drawing and gave some examples, it became an easy task for me. I just had to give my self a chance to listen to the explanation and to investigate more about scale drawing.
Fish A weighing machine The numbers on a measuring instrument Rust and flaky chemicals on metal are called scales 2- The ratio or proportion of size on a map or diagram 2- The ratio or proportion of size on a map or diagram This type of scale we are going to look at today Meaning of the word scale in everyday life
Scale 1-A weighing machine 2-Fish have scales 5- The numbers on a measuring instrument used to make reading 4-Rust and flaky chemicals on metals are called scales 3- The ratio or proportion of size on a map or diagram This is the focus for our lesson.
A Scale drawing Can be shown as fraction: 1/100 or ratio 1: 100 Gives the ratio that compares the measurement of the drawing with the actual measurements. Is a proportional 2 dimensional drawing of an object.
A Scale drawing A scale model Can be shown as fraction: 1/100 or ratio 1: 100 A scale factor Gives the ratio that compares the measurement of the drawing with the actual measurements. Is a proportional 3 dimensional model of an object. The number of times the original has been reduced or enlarged e Is a proportional 2 dimensional drawing of an object.
In scale drawing there are two types of problems: The second type involves making a scale drawing of an object. The first type type involves calculating the real sizes of objects from the drawing.
A- The scale on drawing is 1:100. What is the real distance between two points that are 5 cm apart on the drawing. 1- Calculating the real sizes of objects from drawing 1:100 Means 1 cm on the drawing represents 100 cm in real life 1 cm on the drawing 100 cm in real life Real distance: 5x 100 = 500cm =5m
House design Pool design Scale drawing 1.5 m 15 cm
Why scale drawings? If it's just a small object that you want to represent on paper, full size drawings are great. But, if you want to draw, say, a room with furniture, you're going to need a huge piece of paper to sketch it. As you know, we don't do this. We do "scale drawings" - we make our sketches smaller so they can fit on one sheet of paper.
Why do we need to use scale to draw objects or house plans etc.? We can't fit the true measurements onto a piece of paper.
The ratio 1cm:100cm means that for every 1cm on the scale drawing the length will be 100 cm in real life Plans and maps use a scale. The scale is written as a ratio. The first number in a ratio represents the drawing, while the second number represents the real object. Example: 1:100 Drawing Actual length(Real object) Drawing length: Actual length to
An objet and its scale drawing are similar figures. Two objects are SIMILAR means that they are identical in shape, but not in size.
This house drawing measures 10 cm in length. The scale used here is 1cm:250cm (2.5m) This means that every centimetre on the drawing actually represents 2.5 metres length in real life. If the house (drawing) measures 10cm in length what is the true length of the house? 10x250=2500cm =25m 25m is the true length of the house.
Station 2 Station 3 Station 4 Station 1 Scale drawing stations
(46 to 91 meters) in width (91 to 119 meters) in length Soccer is played on a rectangular field
Terry used a scale of 1 cm representing 1600 cm (16m) when he drew this scale drawing of a soccer field. (1:1600) What are the dimensions of the soccer field? The length of the soccer field is already measured for you. Answer the following questions: The length of the field in the scale drawing (on the diagram) is ______ cm Each centimetre means ______ in real life. Real length of the soccer field= The width of the field on the diagram is ________ cm Real width of the soccer field is __________________ Station1
Terry used a scale of 1 cm representing 1600 cm (16m) when he drew this scale drawing of a soccer field. (1:1600) What are the dimensions of the soccer field? The length of the soccer field is already measured for you. You need to use your ruler to measure the width. The length of the field in the scale drawing (on the diagram) is 6cm. Each centimetre means :1600cm in real life or 16 m Real length of the soccer field= 6x1600= 9600cm= 96 m The width of the field on the diagram is :3 cm Real width of the soccer field is :3x1600=4800cm = 48m Station1 answers
Station2 Calculate the real size of each item: A) Scale: 1cm represents 200cm (1cm:200cm) Use your ruler to measure the length of the flag. Answer: 1- The length of the flag on the drawing is:___________ 2- Each centimetre on the drawing represents 300 cm (3m) in real life. 3- Real length =______________ B) Scale: 1cm represents 15 cm (1cm: 15cm) Answer: 1-The length of the bike on the drawing is:_____________ 2- The real length of the bike is:_______
Station 3 1-Vocabulary with scale drawing Fill in the missing words using the following: Real life - Drawing-Actual -Ratio-Big-Scale 1-A scale drawing is a _________ that compares the measurement of the drawing with the __________ measurements. 2-When we want to draw ______ objects we use ______ drawing. 3-A scale of 1cm: 100m means every cm on the __________ represents 100m in ______ ________. Pool design
Scale: 1:20 What is the length of the bed on the diagram:__________ Real length:_____________ What is the width of the bed on the diagram:___________ Real width:_______________ Station4