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1/26/11 Our Math Goal: To learn about dilations. Copy your homework: page 369 # 1-5 Do the following: “I went to the eye doctor and he dilated my pupils to look inside. What do you think a Dilation is? Then answer the following: Which graph is a Dilation of the top one?
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1/26/11 Our Math Goal: To learn about dilations. Copy your homework: page 369 # 1-5 Do the following: “I went to the eye doctor and he dilated my pupils to look inside. What do you think a Dilation is? Then answer the following: Which graph is a Dilation of the top one? Draw it in your notebook.
Dilation and Geometry Tom draws a triangle on a coordinate plane. Its vertices are (–1, 0), (0, 1), and (1, 0). He then dilates the figure, making its new coordinates (–3, 0), (0, 3), and (3, 0). • What scale factor did Tom use? • Using the graph paper, draw the coordinate grid • Draw the original triangle. Label it A, B, and C. • Draw the new triangle. Label it A’, B’, and C’ • Measure the length of one side in triangle ABC and a corresponding side in triangle A’B’C’ • Use the scale factor formula = new/orig to find the scale factor.
Try it Yourself • The coordinates of a parallelogram are A (-8, 8), B (0, -8), C (0,0), and D (-8,0). • Graph and connect the dots. • Draw (using dotted lines) and label the new parallelogram after a dilation by a scale factor of ½. • Is the dilation an enlargement or reduction?
HSA Problem – MakeUp Quiz • In the diagram below, right triangle RST was dilated with point O as the center of dilation to form right triangle R'S'T'. The area of right triangle R'S'T' is 54 square inches. Determine the scale factor that was used to dilate right triangle RST. Show or explain how you found your answer.