Untitled Slide
Are teachers using the ETCD to understand the specificity of the TEKS?
Translation – a transformation frequently described as a slide of a figure
Algebraic notation
Translation h units horizontally
(x, y) → (x + h, y)
Translation k units vertically
(x, y) → (x, y + k)
Translation h units horizontally and k units vertically
(x, y) → (x + h, y + k)
Reflection – a transformation frequently described as a flip or a mirror image of the original figure
Algebraic notation
Reflection across a vertical axis
(x, y) → (–x, y)
Reflection across a horizontal axis
(x, y) → (x, –y)
Rotation – a transformation frequently described as a turn of a figure around a designated point
Origin as center of rotation
Algebraic notation
Rotation of 90° counterclockwise or rotation of 270° clockwise
(x, y) → (–y, x)
Rotation of 180° counterclockwise or clockwise
(x, y) → (–x, –y)
Rotation of 270° counterclockwise or rotation of 90° clockwise
(x, y) → (y, –x)
Rotation of 360° counterclockwise or clockwise
(x, y) → (x, y)