Digits, Grade 8, Volume 2, Homework Helper

### 10-1: TEKS Practice

• 1. What is the scale factor for the dilation shown?

• 2. ΔRST has vertices R(0,0), S(4,2), and T(2,−2). ΔRST′ is the image of ΔRST after a dilation with center (0,0) and scale factor 1 half . What are the coordinates of point S′?

• 3. The coordinates of ΔLMN are L(1,3), M(3,7), and N(5,5). Draw a graph showing ΔLMN and the image of ΔLMN for the dilation with center (0,0) and scale factor 1 half .

• 4. Writing ΔKLM has vertices K(1,3), L(3,7), and M(7,5). Draw a graph showing ΔKLM and ΔKLM′, its image after a dilation with center K and scale factor 2.

• 5. Reasoning Draw a graph showing ΔDEF′, the image of ΔDEF after a dilation.

• 6. Error Analysis For the dilation with center (0,0) shown on the graph, your friend says the scale factor is 7 halves .

• a. What is the correct scale factor?

• b. What mistake did your friend likely make?

• A. Your friend found the ratio between two sides of the original triangle.

• B. Your friend found the ratio between two sides of the image triangle.

• C. Your friend found the scale factor that enlarges ΔABC′ to ΔABC.

• D. Your friend found the ratio between non-corresponding sides.

• 7. Photography A photographer uses a computer program to enlarge a photograph. When laid on a grid, the original photograph has coordinates P(0,0), H(12,0), O(12,8), and T(0,8). Draw a graph showing rectangles PHOT and PHOT′, its image after a dilation with center at the origin and scale factor 11 over 4 .

• 8. Rectangle QUAD has coordinates Q(5,4), U(5,8), A(10,8), and D(10,4). QUAD′ is the image of QUAD after a dilation with center (0,0) and scale factor 2. What are the coordinates of point D′?

End ofPage 331