Rotating Congruent Triangles

Triangle A is rotated 270° counterclockwise with the origin as the center of rotation to create a new figure. Which rule describes rotating 270° counterclockwise?

• (x,y)→(y, -x) 

• (x,y)→(x,y)

• (x,y)→(-y,x)

• (x,y)→(-x,-y)

What are the series of rigid motions that would map ∆ABC onto ∆A''B''C''?

• a reflection followed by a rotation

• a reflection followed by a translation

• a translation followed by a rotation

• a translation followed by a reflection

Triangle C is rotated 180° clockwise with the origin as the center of rotation to create a new figure. Which rule describes rotating 180° clockwise?

• (x,y)→(y, -x) 

• (x,y)→(-x,-y)

• (x,y)→(x,y)

• (x,y)→(-y,x)

Complete the congruence statement.

• CRP

• PCR

• RPC

• PRC

Select all true statements after the transformations:

• Angle A coincides with angle E.

• Angle B coincides with angle F.

• Segment AB coincides with segment EF.

• Segment BC coincides with segment DF.

• Segment AC coincides with segment ED.

Explain why the image of segment CB lines up with segment CD. The image of ​ (a)   and segment CD ​ (b)   after rotating because we defined our ​ (c)   that way.

• segment CB

• coincide

• rotation

Explain why the image of B coincides with D.Transformations preserve ​ (a)   so the image of point B and point D are the same ​ (b)   along the same ray from C they have to ​ (c)   .

• distance

• coincide

Is triangle ABC congruent to triangle EDC? Explain your reasoning.

• Yes

• No

• E

• F

• EDC