Lesson 2 Circle Dilations Solidify Understanding

Ready

Find the missing angle(s) in each of the figures.

1.

$m ∠ x =$

2.

$m ∠ x =$

3.

$m ∠ x =$

$m ∠ y =$

4.

$m ∠ q =$

$m ∠ r =$

$m ∠ s =$

Find the angle of rotational symmetry for each regular polygon. (Note: A figure has rotational symmetry if it can be rotated by an angle between $0 °$ and $360 °$ so that the image coincides with the pre-image. The angle of rotational symmetry is the smallest angle for which the figure can be rotated to coincide with itself.)

5.

6.

Set

7.

If $⨀ A$ and $⨀ K$ are similar, locate the center of dilation.

If the black, solid circle $A$ and the red, dotted circle $A$ are similar, locate the center of dilation.

Which of the circles in the figure are similar? Justify your answer.

The radii for each of the circles in Figure 2 are $A D = 21$ , $A C = 15$ , and $B P = 6$ .

8.

What is the scale factor that dilates the circle with radius $A C$ to the circle with radius $A D$ ?

9.

What is the scale factor that dilates black, solid $⨀ A$ to $⨀ B$ ?

10.

If the circumference of black, solid $⨀ A$ is $95 inches$ , what is the circumference of $⨀ B$ ?

Go

Construct the line of reflection between the image and the pre-image. Then write the equation of the line of reflection.

11.

Equation:

12.

Equation:

13.

Draw the radius of the circle. (Note: The definition of radius requires you know or can locate the center of the circle. Construct the center before you draw the radius.)

14.

Draw the diameter of the circle. (Note: The definition of diameter requires you know or can locate the center of the circle. Construct the center before you draw the diameter.)