How To Make A Scale Drawing

Maps and scale drawings

Maps and scale drawings form a crucial part of everyday life. Scale drawings are useful in a variety of careers from surveyors, to town planning and architecture. We also need to understand bearings.

Scale drawings

Scale drawings are used to design a broad range of different projects. Gardens, kitchens and even spacecraft have all been constructed by following a scale drawing.

Look at this scale drawing:

A floorplan of a house measuring 8.3 x 10.9

It is a design for a bungalow. You should notice that the dimensions for the rooms are in millimetres. This is common in the building trade as precision is very important. The dimensions for the outside are in metres.

There are three types of questions you can be asked when studying scale drawings:

the first type involves calculating the scale factor of the drawing, in other words what scale label should be present on the diagram
the second type of question you could be asked is to work out how large an object from a plan is in real life using measurements and a given scale
finally, you could be asked to produce a scale drawing from a given scale factor and measurements

Question

Ben is producing a scale drawing of a swimming pool he plans to build. The pool's dimensions are 2 m by 6 m. When he measures the drawing on his plan he sees that it is 8 cm by 24 cm. What scale should he include on his plan?

To answer this question you should use the same units. The question uses metres and centimetres, so change everything to centimetres.

From the information present, we can see that in Ben's drawing 8 cm = 200 cm in real life.

We can divide 200 by 8 to see what 1 cm represents:

200 ÷ 8 = 25

The scale he should use is 1cm:25cm or simply 1:25

Question

James is using an internet tool to design his ideal skateboard park. The scale on the design is 1:150. James measures the drawing dimensions to be 10 cm by 13 cm. What size would his skateboard park be in real life? Give your answer in metres.

An isometric drawing of a skateboard park

15 m by 19.5 m

First, he must convert his measurements using the scale factor:

10 × 150 = 1,500 cm

13 × 150 = 1,950 cm

Then we must convert these into metres by dividing by 100:

1,500 ÷ 100 = 15 m

1,950 ÷ 100 = 19.5 m

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