Scale Factor & Scale Drawings. Understanding Scales. All scale drawings must have a scale written on them. Scales are usually expressed as ratios. Normally for maps and buildings the ratio: Drawing length: Actual length For maps the ratio is normally in the ratio:
Scale Factor &
All scale drawings must have a scale written on them. Scales are usually expressed as ratios.
Normally for maps and buildings the ratio:
Drawing length: Actual length
For maps the ratio is normally in the ratio:
Map distance: Actual Distance
Example: 1cm : 100cm
The ratio 1cm:100cm means that for every 1cm on the scale drawing the length will be 100cm in real life
The ratio 1:10000 means that the real distance is 10000 times the length of one unit on the map or drawing.
How to find Scale Factor
Scale factor = new measurement
Old measurement x SF = new measurement
This HO gauge model train is a scale model of a historic train. A scale model is a proportional model of a three-dimensional object. Its dimensions are related to the dimensions of the actual object by a ratio called the scale factor. The scale factor of an HO
gauge model train is .
This means that each dimension of the model is of the corresponding dimension of the actual train.
A scale is the ratio between two sets of measurements. Scales can use the same units or different units. The photograph shows a scale drawing of the model train.
A scale drawingis a proportional drawing of an object. Both scale drawings and scale models can be smaller or larger than the objects they represent.
If you have ever seen Jurassic
Park, you saw how big the
dinosaurs were compared to the
people. Pretend that they made
a large Human to watch over the
animals. What would be the scale
factor if a 64 inch person was
made to be 160 feet?
The scale factor tells you
how many times bigger than
normal that person really is.
You must make all units of
measure the same.
160 x 12
Now take the:
This means that the person
was created 30 times his
The scale factor of the pool is
1 to 20 yards.
units in the same fraction.
Inches = yards
Setting up Proportions
Tom is drawing a blueprint for a rectangular shed he wants to build. The scale factor is 1 ft. to inch. If the dimensions of the blueprint are 1 in. by 2 inches, what are the actual dimensions of the shed going to be?
Write a Proportion
Using Scale Factor
inch to 1 foot
If the length in inches is 2 inch, what would the actual length be in feet ?
Write a ProportionUsing a Scale Factor
What are scale drawings?
Scale drawings are everywhere!
Footprints of houses
Can you think of any more?
Scale 1 cm = 1 m
Length of units = 6 m
Scale in everyday life: kitchen design
Scale in everyday life: maps
Scale 1 : 1 000 000
Scale in everyday life: plans
Scale 2 cm = 1 m
Using A Scale Drawing
When objects are too small or too large to be drawn or constructed at actualsize, people use a scale drawing or a model.The scale drawing of this tree is 1:500If the height of the tree on paper is 20 inches, what is the height of the tree in real life?
The scale is the relationship between the measurements of the drawing or model to the measurements of the object.
In real-life, the length of this van may measure 240 inches. However, the length of a copy or print paper that you could use to draw this van is a little bit less than 12 inches
Ratios and proportions can be used to find distances using a scale.
1 inch = 15 miles
The distance from Jacksonville to Smithtown on a map is 4 inches. How many miles are between these cities?
The distance between the two cities is 60 miles.
n = 60