Vocabulary
How do you solve to determine if 2 ratios are equivalent?
cross multiply or simplify the ratios
Triangle ABC is similar to triangle GHI. Which side corresponds to side BC?
side HI
You have a triangle with sides of 2 in, 4 in, and 3 in. What would the new sides be with a scale factor of 2?
6 in, 8 in, 10 in
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
Corresponding angles of congruent figures are congruent.
True, because congruent figures are exactly the same in size and shape.
What do two shapes have to be to be similar?
same shape, proportional
Rectangle DEFG is similar to Rectangle MNOP. Which side corresponds to side DE?
side MN
Are these proportional?
rectangle with lengths 5 in and 10 in, and rectangle with lengths 4 in and 9 in
NO
A scale drawing of your house uses the scale 1 cm: 3 feet. If the actual measure of the porch is 39 feet, what will the measurement be on the scale drawing?
You must use the correct units!
13 cm
Corresponding sides of similar figures are congruent.
Lie, because similar figures have the same shape and proportional (but different) side lengths.
What is true about the angles of similar figures?
corresponding angles are equal
Parallelogram TUVW is similar to parallelogram CDEF. Which side corresponds to side CF?
side TW
You have a new triangle of A'B'C' with side lengths of 7.5, 8, and 10. What would the original side lengths be if the scale factor was 1/2?
15, 16, 20
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
Corresponding angles of similar figures are identical.
True, because having identical measures is one of the requirements of similar figures.
What is an equivalent fraction to 4/7?
8/14, 12/21, 40/70
Pentagon CDEFG is similar to pentagon PQRST. Which side corresponds to side EF?
side RS
Triangle ABC has side lengths of 15, 30, and 45. Your new triangle A'B'C' has side lengths of 5, 10, and 15. What scale factor was used to get the new triangle?
1/3
You take a photograph of Mount Monadnock (a mountain in NH). Monadnock is about 3000 feet high. If the photo scale is 1 mm: 200 feet, what is the height of the mountain in the photo?
15 mm
All right triangles are similar.
Lie, although all right triangles share one common angle measure (90 degrees), the other two angles are not necessarily the same--which means the triangles may not be similar.
What is true about the sides of similar figures?
corresponding sides are proportional
Rectangles BDEF and PSTR are similar. Name a pair of corresponding sides.
BD and PS, DE and ST, EF and TR, or BF and RP
You have a triangle with sides 6, 8, 10. What are the new side lengths if you use a scale factor of 3.6?
21.6, 28.8, 36?
Daily Double! A 40 ft. tall building casts a shadow that is 20 ft. long. If a nearby flagpole is 20 ft. tall, how long will its shadow be?
10 ft.
All squares are similar.
True, all squares have the same angle measures, and their sides will be proportional. So any square is similar to any other square.