GRADE 7 MATHEMATICS (7.6) Geometry and spatial reasoning. The student compares and classifies shapes and solids using geometric vocabulary and properties. The student is expected to: (D) use critical attributes to define similarity.

Sketch and label 2 other triangles that would be similar to triangle ABC and justify your sketches. Sketch 2 triangles that would not be similar to triangle ABC and justify your sketches. C 6

9

A

B

12

Similar Triangles: Sketch 1:

Justification:

Sketch 2:

Justification:

Triangles that are not similar: Sketch 1:

Justification:

Sketch 2:

Justification:

1. What mathematical concepts and vocabulary do I need to know to be able to work this problem? 2. Will the Grade 7 Mathematics Formula Chart be helpful on this problem? Why or why not? 3. Will a picture or diagram be helpful on this problem? If so, how?

4. What problem-solving strategy or strategies will I use to help solve this problem? 5. Extension (7.6D): What is the scale factor you used to create the first triangle that is similar to the given triangle? TEKSING TOWARD TAKS ÂŠ 2006

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GRADE 7 MATHEMATICS (7.6) Geometry and spatial reasoning. The student compares and classifies shapes and solids using geometric vocabulary and properties. The student is expected to: (D) use critical attributes to define similarity.

Sketch and label 2 other triangles that would be similar to triangle ABC and justify your sketches. Sketch 2 triangles that would not be similar to triangle ABC and justify your sketches. C 6

9

A

B

12

Triangles that are similar: Sketch 1:

Justification:

Sketch 2:

Justification:

Triangles that are not similar: Sketch 1:

Justification:

TEKSING TOWARD TAKS ÂŠ 2006

Sketch 2:

Justification:

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GRADE 7 MATHEMATICS (7.6) Geometry and spatial reasoning. The student compares and classifies shapes and solids using geometric vocabulary and properties. The student is expected to: (D) use critical attributes to define similarity.

If the corresponding sides of two rectangles are proportional, then the two rectangles can be classified asA

congruent

B

similar

C

regular

D

reflections

If the corresponding base angles of two isosceles triangles are congruent and the bases are proportional then the two triangles can be classified asA

congruent

B

similar

C

regular

D

reflections

Which of the following statements is true? A

All right triangles are similar.

B

All isosceles triangles are similar.

C

All squares are similar.

D

All rectangles are similar.

Triangle ABC is similar to triangle DEC. Segment AB is parallel to segment ED. A

12

B 8

6 C x E

D 20

Which rectangle is similar to rectangle ABCD? 10 cm

A

B 4 cm

D

Which of the following proportions can be used to find the value of x?

A

12 20

x  8

C

4 cm

B 2 cm

A

6 cm B

C 2 cm

5 cm

D 2.5 cm

C

12

8  20 x

12

x  20 6

12

20  6 x

5 cm D

2 cm