In geometry, two figures are congruent if they have the same shape and size. In this case, triangle ACB and triangle DFE are congruent if they have exactly the <u>same three sides and exactly the same three angles</u>.
SSS property <em>(side, side, side)</em>states that two triangles have all three sides equal. This means that:
Side AC and side DF are equal (<em>marked with one line</em>)
Side CB and side FE are equal (<em>marked with two lines</em>)
Side BA and side ED are equal (<em>marked with three lines</em>)