Angles A and P are marked congruent; angles B and Q are marked congruent, so the triangles are similar by the AA similarity postulate. The similarity statement can be written ...
ΔABC ~ ΔPQR by AA similarity
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The ratio of sides of PQR to ABC is the ratio QR/BC = 12/6 = 2. That is, each side in the larger triangle is 2 times the length of the corresponding smaller side.
The response variable is the dependent variable whose variation depends on other variables and in this case it is the type of surgery either total knee replacement or partial knee replacement.
While the explanatory variable which is the independent variable manipulated by the researcher for the given experimental study is the amount of activity the patients were able to do after their respective surgeries.
