scale drawing – a proportional two- dimensional drawing of an object scale factor – the ratio...
TRANSCRIPT
Scale drawing – a proportional two-dimensional drawing of an object
Scale factor – the ratio used to enlarge or reduce similar figures
Scale model – a proportional three-dimensional model of an object
Scale – the ratio between two sets of objects
Create a ratio comparing the figures Next, simplify the ratio Ex. Use either lengths or heights to
create the ratio to find the scale factor : 11/132 or 5.5/66
Simplify: ÷ by 11: 1/12 or 1/12Race Car
Model
Length (in.) 132 11
Height (in.) 66 5.5
Set up a proportion using the scale factor to find the unknown length
Cross multiply and then divide
A photograph has dimensions 5.4 cm and 4 cm. The scale factor is 1/15. Find the size of the actual painting: photo/painting = 1/15› 5.4/l = 1/15 or 4/w= 1/15 l = 81 cm w = 60 cm Dimensions of actual painting: 81cm x 60 cm
Using scale factor to find distance Set up proportion using scale factor
and cross multiply and then divide to find missing distance