Question:
State SSS similarity criterion.
Solution:
SSS Similarity Criterion: If the corresponding sides of two triangles are proportional, then they are similar.
In ΔABC and ΔDEF, if
$\frac{\mathrm{AB}}{\mathrm{DE}}=\frac{\mathrm{BC}}{\mathrm{EF}}=\frac{\mathrm{AC}}{\mathrm{DF}}$
Then, $\triangle \mathrm{ABC} \sim \triangle \mathrm{DEF}$