The number side lengths are multiplied by to get the side lengths of a similar shape.
What is the Scale Factor
Find the height of the tree, h.
16 ft
Triangle ABC is similar to triangle GHI. Which side corresponds to side BC?
side HI
Write a ratio of 15 boys to 12 girls
15 to 12
15/12
15:12
Scale factor of 2
The comparison of two things (ex: length to width)
What is a Ratio
2.5 cm
Rectangle DEFG is similar to Rectangle MNOP. Which side corresponds to side DE?
side MN
A class has 12 students who like football and 5 who do not like football. Write a ratio of students who do not like football to those who like football.
5 to 12
Whats the Scale Factor?
1.5
Exactly the same shape and size
Congruent
A map uses the scale 1 inch: 7 miles. The distance on the map is 5 inches. What is the actual distance represented by the map?
You must use the correct units!
35 miles
Parallelogram TUVW is similar to parallelogram CDEF. Which side corresponds to side CF?
side TW
A scale model of a boat uses a scale of 1inch: 2 feet. What is the actual size of the boat if the model boat is 20 inches long?
You must use the correct units!
40 feet
How does the Scale Factor affect the perimeter of a figure?
The perimeter changes by the scale factor.
What must be true for shapes to be similar?
- shape
-Angles are equal
-Have a scale factor or equal ratios
The _________ method helps us find heights of objects that are difficult to measure directly.
When is our unit test?
Thursday
Write an equivalent ratio (proportion) to the ratio 4:5
8:10 or others
12:15
16:20
What is the scale factor from the shadow of the wall to the shadow of the tree?
4
Describe corresponding sides
Corresponding sides are the sides in the same position on two different figures
Use the picture to find the height of the tree.
10 ft
Daily Double! ΔPQR is similar to ΔSTU What side corresponds to side UT?
ΔRQ
Write a ratio (length to width) that would help you solve the following two similar triangles.
21/x = 24/16
How does the Scale Factor affect the area of a figure?
The area changes by the scale factor times the scale factor or the scale factor squared. Example, if the scale factor is 3, the area changes by 9.