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Home > CC3 > Chapter 8 > Lesson 8.3.1 > Problem 8-128

8-128.

The two triangles at right are similar shapes. Homework Help ✎

  1. What is the scale factor between shape A and shape B?

    Which corresponding sides in A and in B are both known?

    What do you need to multiply by to get ?

  2. Find the missing sides.

    Identify which sides in A correspond to which sides in B.

    Since corresponds to and corresponds to , multiply by the scale factor to find , and divide by the scale factor to find .

  3. If you wanted to make shape A smaller instead of bigger, what is a scale factor you could use?

    The scale factor is what you multiply by to increase or decrease the size of a shape.

    If a scale factor greater than one created a larger triangle, then a scale factor less than one must create a smaller triangle.
    Note that a scale factor cannot be negative because a negative side length is nonexistent.