Revision sheet

All the summary cards of the chapter on one page. Print it, or save it as a PDF from the print window.

Dilations

$(x, y) \to (kx, ky)$ about the origin; lengths × $k$ , angles kept.

Watch out: multiply, do not add.

Similar figures

Lengths × $k$ , perimeters × $k$ , areas × $k^2$ .

Watch out: scale by multiplying, and square $k$ for areas.

Triangle similarity

AA (or SSS, SAS similarity) → corresponding sides proportional.

Watch out: AA works for triangles only.

Slope

Rise over run, the same for every slope triangle on the line.

Watch out: down from left to right means negative.

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