Similar Triangles
Ratios
The ratio of 3 to 4 can be written as 3:4 or 
Example of ratios
3 cups of milk to 5 cups of flour
8 ounces of 2-cycle oil: 2 gallons of gasoline
15 shots made to 20 shots attempted
8 passes completed to 11 passes attempted
Solving proportions
Find the missing
value.
1)
2)
3)
Using ratios to find
the missing side of a triangle
CSSTP
Corresponding sides of similar triangles are proportional
Given
, find x and y.
Find y
Find x
More Examples
1)
2)
3)
4) With 100 ft of string out a kite is 64 ft above the ground. When a girl flying the kite pulls in 40 ft of the string, the angle formed by the string and the ground does not change.
What is the height of the kite above the ground after she pulls in 40 feet of the string?
Area of Big Square = Area of Little Square + 4(Area of the Triangles)
Perspective
Types of perspective
1) Overlapping shapes: In overlapping shapes depth perception is created by using overlapping shapes.
Photos courtesy: http://fog.ccsf.cc.ca.us/~rholbert/dezin.html
2) Diminishing sizes: In diminishing sizes depth is created by systematically making objects smaller.
3) Atmospheric Perspective: In atmospheric perspective depth is created by making objects that are farther away less clear by diminishing both color and shading.
4) One-Point Perspective: In one perspective depth is creating by using a vanishing point.
Photo courtesy of
http://www.cartage.org.lb/en/themes/Arts/drawings/PerspectiveDrawing/OnePointPersp/OnePointPersp.htm
http://facweb.cs.depaul.edu/sgrais/images/Lec2/france10.jpg
Identify the
perspective
1)
2)
3)
4)
http://www.frick.org/html/pntg6df.htm
Perspective and
Proportions
Examples
1) Find
2) Find x
Exercises on page
286-297
22)
20)
