2. Use the Mira to determine whether these following symbols were properly reflected using a Mira. If they were, draw the reflection line using the

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1 Mira Exercises What is a Mira? o Piece of translucent red acrylic plastic o Sits perpendicular to the surface being examined o Because the Mira is translucent, it allows you to see the reflection of objects on the near side and also see through the Mira to the objects on the far side Using the Mira o When using the Mira always place the beveled edge down and toward you The beveled edge allows you to properly draw lines where the center of the edge of the reflection wall would be o When drawing a line along the edge of the Mira, always draw it along the beveled edge Example: Place your Mira on the dotted line of reflection below. Look through the left side of the Mira to see the reflected object on top of the object on the opposite side of the Mira. 1. Write your name on the left side of the dotted line below. Then place your Mira on the line and look through the left side of the Mira to see the reflection of your name. Trace your name on the opposite side of the Mira with that reflection.

2 2. Use the Mira to determine whether these following symbols were properly reflected using a Mira. If they were, draw the reflection line using the beveled edge.

3 3. Use the Mira to draw a reflection of the following images. Make sure to properly label the corresponding vertices on the reflected image. For example vertex A on the original image would be labeled as A on the reflected image. Also be sure to draw your reflection lines with the beveled edge. A B C E F H G I J

4 How can a Mira be used in Math? o Can be used to find a perpendicular bisector of a line o Can be used to find the bisector of an angle Example: Look at the image below. The dotted line is the perpendicular bisector of the solid line. Place your Mira on the dotted line and look through the left side of the Mira to see how the reflected portion of the line is directly on top of the line on the opposite side of the Mira. This shows that the Mira is perpendicular to the solid line. Also notice how the left endpoint is reflected on top of the right end point. This shows that the Mira is bisecting the solid line. Move your Mira up and down the solid line to see how the reflected end point moves. 4. Find and draw the perpendicular bisector of the following line using your Mira.

5 Example: Look at the image below. The dotted line is the bisector of the angle made below by the solid lines. Place your Mira on the dotted line and look through the left side to see the left line reflected on top of the line on the opposite side. This shows that Mira is bisecting the angle. Rotate your Mira around the point of intersection of the two solid lines to see how the reflected line moves. 5. Find and draw the bisector of the following angle using your Mira.

6 6. CHALLENGE QUESTION: Use your Mira to construct an equilateral triangle with the given line segment. Hint: Think about the properties of an equilateral triangle. 7. CHALLENGE QUESTION: Use your Mira to construct a square with the given line segment. Hint: Think about the properties of a square.

7 End Discussion Ask them what are the properties of a Mira o Mira sits perpendicular to the surface being used o Allows you to see the reflection of objects on one side while allowing you to see objects on the other side through the Mira o An object s reflection may not appear the same as the actual object because it is a mirror image Ask them how do you use the beveled edge and why is it important o The beveled edge needs to be down on the surface and towards you o The beveled edge allows you to properly draw lines where the center of the edge of the reflection wall would be Ask them how they can use a Mira in math o Finding perpendicular bisectors of lines o Finding bisector of angles o (If we get to challenge questions and complete them) Have a student explain how those properties were used to complete the challenge questions