Scale Flashcards

All 6 cards in this deck

What does a scale of $1:50$ mean?

$1$ unit on the drawing represents $50$ of the same units in real life.

How do you convert a length measured on a map into the real length?
e.g. $4$ cm on a map of scale $1:25\,000$

Multiply the measured length by the scale factor.
$4 \times 25\,000 = 100\,000$ cm $= 1$ km

How do you convert a real length into the length to draw on a scale drawing?
e.g. real length $40$ m, scale $1$ cm represents $5$ m

Divide the real length by the scale.
$40 \div 5 = 8$ cm

For a scale of $1:n$, what is the scale factor for areas?

$n^2$.
e.g. for $1:50$ the area scale factor is $2500$.

What are the steps to plot a point on a scale drawing from a distance and a bearing?
e.g. $B$ is $6$ km from $A$ on a bearing of $070°$, scale $1$ cm represents $2$ km

1. Convert the real distance to a drawing length: $6 \div 2 = 3$ cm.
2. Draw a north line at $A$ and measure $070°$ clockwise from it.
3. Draw $3$ cm along that direction and label the end $B$.

True or false? On a plan with scale $1:100$, an area of $1\text{ cm}^2$ on the plan represents $100\text{ cm}^2$ of real area.

False. Areas scale by $100^2 = 10\,000$, so it represents $10\,000\text{ cm}^2$.