19.
Given
- window width and height are in proportion to building width and height
- window width and height are 11 in and 18 in, respectively
- building height is 108 ft
Find
Solution
The proportional relation can be written as
... (building width)/(building height) = (window width)/(window height)
Multiplying by (building height) gives
... (building width) = (building heigh) × (window width)/(window height)
... (building width) = 108 ft × (11 in)/(18 in)
... building width = 66 ft
21.
Given
- map distance = 6.75 in
- map scale = 1.5 in : 5 mi
Find
Solution
The distances are in proportion, so
... (map distance) : (actual distance) = 1.5 in : 5 mi
Multiplying by (5 mi)/(1.5 in)×(actual distance), we have
... (5 mi)/(1.5 in)×(6.75 in) = (actual distance) = 22.5 mi