Question

What set of reflections would carry triangle ABC onto itself?

Answer 1

y-axis, x-axis, y-axis, x-axis

x-axis, y=x, y-axis, x-axis

x-axis, y-axis, x-axis

y=x, x-axis, x-axis

Answer 2

What do you think?

Answer 3

Which set of reflections will bring it right back to where it started from?

Answer 4

Consider a point (x, y) and think about what each reflection will do to the point. Which set will take (x, y) -> (x, y)?

Answer 5

For example, look at the last option:

y=x take (x, y) to (y, x)

x-axis takes (y, x) to (y, -x)

x-axis takes (y, -x) to (y, x)

So that isn't it.

Answer 6

@DebbieG

Answer 7

still need help here, not grasping it at all.

Answer 8

would it be x-axis, y-axis, x-axis?

Answer 9

@ganeshie8

Answer 10

///
x-axis, y-axis, x-axis?

nope, observe that reflecting in y-axis two times brings u back to where u started

Answer 11

or, reflecting in x-axis two times brings u back to where u started

Answer 12

so to nullify the reflection, u may need to reflect two times in each axis