Honors Geometry 7.1 Notes
Ratio
Expression that
compares two quantities
by division.
Examples:
Proportion
An equation involving ratios.
"Proportional"
and
Must be true if the
proportion is true.
The ratios
form a
True Proportion.
Honors Geometry 7.1 Notes
Examples:
Honors Geometry 7.1 Notes
Honors Geometry 7.1 Notes
"Extended Ratios"
Say the ratio of 3 quantities is a:b:c
That means....
first two quantities compare by: a:b
last two quantities compare by: b:c
and
first and last quantities compare by a:c
Honors Geometry 7.1 Notes
Example:
Honors Geometry 7.1 Notes
Example:
Honors Geometry 7.1 Notes
Thoughts about Proportions from the BOOK:
"If a proportion is 'TRUE' then the
product of the extremes is always
equal to the product of the means."
ad = bc
Honors Geometry 7.1 Notes
All of these proportions are
EQUIVALENT.
(Notice what happens when you cross multiply.)
7-1: 10 - 29, 31 - 37, 54 - 59