Translating and reflecting shapes
Draw and translate simple shapes on the coordinate plane; reflect shapes in the axes
What a learner can do afterwards
- Translate a triangle 3 units right and 2 units down on a coordinate grid and state the new coordinates
- Reflect a shape in the x-axis and list the coordinates of the reflected vertices
- Explain how translation changes coordinates (add/subtract) while reflection changes the sign of one coordinate
1 · Read
A translation slides a shape without turning it or flipping it. Every point on the shape moves the same distance in the same direction. On a coordinate grid, moving right or left changes the x-coordinate, and moving up or down changes the y-coordinate.
A triangle has corners at (1, 1), (4, 1), and (2, 3). Translate it 3 units right and 2 units down. Add 3 to every x-coordinate and subtract 2 from every y-coordinate. The new corners are (4, -1), (7, -1), and (5, 1).
A reflection flips a shape across a line, like a mirror. Reflecting a shape in the x-axis keeps every x-coordinate the same but flips the sign of every y-coordinate. Reflecting in the y-axis works the other way: the y-coordinate stays the same, and the x-coordinate flips sign. A slide is different: it adds or subtracts the same amount from each coordinate instead of changing a sign.
A triangle has corners at (1, 2), (3, 2), and (2, 4). Reflect it in the x-axis. Keep each x-coordinate the same and flip the sign of each y-coordinate. The new corners are (1, -2), (3, -2), and (2, -4).
Translating is a slide: add or subtract the same number from every point. Reflecting is a flip: only one coordinate changes sign, and the other stays exactly the same.
Translating slides a shape by adding or subtracting the same amount from every coordinate; reflecting flips the sign of one coordinate while the other stays the same.
Reflection practice adapted from University of Missouri materials with unverified terms. Videos by Khan Academy.
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Take it off screen
Where it sits
This opens up
Where this leads
Jobs that lean on this skill. Follow one to see everything it is built on.
13 questions wait behind this lesson, each with its answer explained. Every answer feeds the sky: stars light as they are learned, and dim when it is time to come back.