How To Draw To Scale With Fractions

3 Calibration drawings

Have you always drawn a plan of a room in your firm to assist you piece of work out how to rearrange the furniture? Or maybe you've sketched a plan of your garden to aid yous decide how big a new patio should be?

These pictures are called scale drawings. The important thing with scale drawings is that everything must exist drawn to scale, meaning that everything must be in proportion – that is, 'shrunk' by the same amount.

All scale drawings must accept a scale to tell us how much the drawing has been shrunk by.

Instance study _unit5.3.1 Example: In the garden

Here is an example of typical scale cartoon:

Described image

Figure _unit5.three.1 Figure sixteen A scale cartoon of a garden

What's the width and length of the patio?

Box _unit5.3.i

Hint: This scale drawing has been fatigued on squared paper. This makes it easier to draw and empathize. Each square is 1 cm broad and 1 cm long. So instead of using a ruler you can just count the squares and this will tell y'all the measurement in centimetres.

Method

The scale in this drawing is one:100. This ways that i cm on the scale drawing is equal to 100 cm, or 1 thou, in real life. Once we know the scale, we tin can mensurate the distances on the drawing.

Using a ruler (or just counting the squares), nosotros find that the patio is 5 cm long and 3 cm wide on the drawing. This ways that in real life it is five metres long and 3 metres broad.

And then when yous're working with scale drawings:

Find out what the scale on the cartoon is.
Measure the altitude on the drawing using a ruler (or count the number of squares, if that's an option).
Multiply the distance yous mensurate by the scale to give the distance in real life.

Now try the following action. Recall to check your answers in one case yous have completed the questions.

Activity _unit5.3.1 Activeness 6: Getting information from a calibration drawing

Permit'southward stay with this scale drawing of the garden.

Effigy _unit5.3.two Figure 17 A scale drawing of a garden
- a.What is the width and length of the vegetable garden?
- b.What is the width and length of the flower bed?
- c.How far is the patio from the vegetable garden?
- d.Say y'all wanted to put a trampoline between the patio and the vegetable garden. It measures 3 1000 by 3 m. Is in that location enough space for it?
A landscaper wants to put a wild area in your garden. She makes a scale plan of the wild area:

Figure _unit5.3.3 Figure 18 A scale drawing of a wild area of a garden

What is the length of the longest side of the actual wild area in metres?
Here is a scale drawing showing i disabled parking space in a supermarket auto park. The supermarket plans to add two more disabled parking spaces adjacent to the existing one, with no spaces between them.

Figure _unit5.3.4 Figure 19 A scale drawing of a machine park

What will be the total actual width of the three disabled parking spaces in metres?

Answer

The answers are every bit follows:
- a.The vegetable garden is 5 m long and 2 m wide.
- b.The flower bed is 6 m long and two g wide.
- c.The patio and vegetable garden are iii grand autonomously.
- d.The distance between the patio and vegetable garden is 3 m and the trampoline is 3 m wide. So the trampoline would fit in the space, but it would be a bit of a squeeze.
The length on the drawing is 9 cm, and the scale is 1:50. This means that 1 cm on the cartoon is equal to 50 cm in real life. So to find out what 9 cm is in real life, you need to multiply it past 50:
- 9 × 50 = 450 cm
The question asks for the length in metres, so you demand to convert centimetres into metres:
- 450 ÷ 100 = iv.v m
The actual length of the wild area will be iv.5 yard.
You need to find out the width of three disabled parking spaces. The width of one parking infinite on the calibration drawing is 2 cm, so start you need to multiply this by 3:
- 2 × three = six cm
The scale is i:125. This ways that 1 cm on the drawing is equal to 125 cm in real life. So to find out what 6 cm is in real life, yous need to multiply it by 125:
- 6 × 125 = 750 cm
The question asks for the length in metres, so you need to convert centimetres into metres:
- 750 ÷ 100 = 7.5 m
The actual width of all iii parking bays will be 7.v thou.