Congruence Exploration 2 - Reflections in Intersecting Lines

Work with a partner.

Draw a scalene triangle and label it triangle ABC. a. Draw any line DE. Reflect triangle ABC in line DE to form triangle A'B'C'. b. Draw any line DF so that angle EDF is less than or equal to 90 degrees. Reflect triangle A'B'C' in line DF to form triangle A''B''C''.

c. Find the measure of angle EDF. Rotate triangle ABC counterclockwise about point D using an angle twice the measure of angle EDF.

d. Make a conjecture about the figure reflected in two intersecting lines. Test your conjecture by changing triangle ABC and the lines.

f. From Exploration 1 and 2, what conjectures can you make about a figure reflected in two lines?